Today I have an update for you on my aquaponics adventures. The system has
been up and running all season (April 20 – November 1) so there is a lot
of information to be shared. The system currently includes 12 beds – 4
outdoors and 8 in a greenhouse – for a total surface area of 56 sq.ft (~
5.5 m2). An in-depth description of the system was published last year on
Survivalblog. I made only 1 substantial change since then and that is in
the way the polyethylene drain pipes are connected to the beds. The
connections need to be made with threaded nipples/tees otherwise the
system will continually leak. You will need to put a threaded ring on the
nipple before you screw it through the bottom of the bed into the tee.
This allows proper stabilization of the connection. I made the ring by
cutting a slice 1-1.5 threads deep off the tee which has more threads than
you need anyway. If you collect the drain water in a gutter underneath the
beds, you won’t have this problem but then you have to clean the gutters
at least once a month of algae growth.
Before I get to yield discussion and crop notes, there are a few points
that I want to bring to your attention. Last year I mentioned some of my
reasons for putting in a aquaponics system but I feel I should spend some
more time on that. I know gardeners take pride in their craft and are
trying to do the best they can under the circumstances; regardless if you
are shooting for the biggest pumpkin, highest yield or favor an organic
approach. I, too, have spend most of my life taking care of dirt gardens
and trying something totally new and unknown can be a daunting exercise.
Nevertheless as circumstances change we do well to re-evaluate our methods
from time to time. Like most I have been told that survival is for
fittest. This idea seems to go back to Mr. Darwin’s trip to the Galapagos
islands where he found lots of songbirds each of which was well adapted to
a particular niche in the ecosystem. I should point out that I have
reservations whether this observation justifies the ‘survival of the
fittest’ ideas. It does if you define fittest as the best adapted
individuals. If you define fittest as ‘biggest bad*ss’, I suggest Mr.
Darwin’s observations lean toward the opposite. At any rate, I decided to
follow nature’s lead and look for an approach to gardening that is more
adaptable than a run-of-the-mill dirt garden.
aquaponics seemed to be the most promising approach because it can be
adapted to almost any situation. In no particular order:
– Aquaponic garden has a much smaller footprint due to higher yields,
longer growing season.
– Easy to cover against frost or precipitation due to small footprint.
– Less work throughout the season. Once everything is growing you check
the water level (add some if needed) and the fertilizer level (add some if
needed). During hot weather I had to add water every day. Early summer and
fall as little as once a week. Since my holding tank (which I also use to
create manure tea) is located above the collection tank, most of the time
that meant opening a valve and closing it again once the collection tank
was full enough.
– Relocating: I need about a day to dismantle the system and another two to
put it back together when working alone.
– Legal problems: The desire of bureaucrats and big business is to control
your life, including what you eat. As far as I know there are no laws
specifically against gardening yet (use of heirloom seeds is debatable
since a 1% contamination with GMO seeds could land you in legal trouble
but if it gets to that point a small system is much easier to conceal.
– No decent/good land available: that’s okay, I don’t need any. Plants seem
to thrive in just about any medium as long as its kept moist and aerated.
– Lower fertilizer usage due to no leaching by ground water / adsorption
to soil.
– Decreased use of chemicals: quick growing healthy plants are better able
to fend off attackers and soil borne diseases are eliminated. Plants also
can’t pick up chemical residue from the soil. Here you can read up on
glyphosate and why you want to grow as much of your own food as you
possibly can.
– Droughts/water shortages aren’t a problem as the system gets by on
10-15% water usage compared to conventional crop raising methods.
- Climate warming: not an issue; might use a bit more water but plants can
be easily shaded.
– Climate cooling: more of an issue for me due to my location. Our growing
season for a dirt garden is roughly May 20 – September 1. A drop in
temperatures of 2C would probably shorten my season by several weeks and
cause slower growth throughout the remainder, resulting in a number crops
barely reaching maturity and definitely have lower yields. I do not have a
lot of leeway as I already have to use short season varieties. Solar cycle
activity and increased volcanic activity both say we are heading in this
direction; recent presidential executive order notwithstanding.
- Power usage: I know there are people who believe that aquaponics takes a
lot of energy but this is only true if you waste your energy in a poorly
designed and/or run system. What you DO need is a reliable power supply
i.e. photovoltaics. My system ran the entire season on a 60W panel and
during May, June, July and early August the controller routinely
disconnected the panel in the afternoon to prevent the batteries from
overcharging. During October when we had cloudy weather for days on end
battery voltage dropped to around 12.3V resting voltage but this is no
cause for concern.
I will have more notes on the system itself later on but lets take a look
at the crop results first:
Red beets – 5 lbs
Onions – 8 lbs
Turnips – 7 lbs
Potatoes – 5 lbs (mostly small tubers – lower ones showing wet rot)
Green beans – 4 lbs
Pole beans – 6 lbs (3 plants – slicing variety)
Tomatoes – 10 lbs (cherry type – 3 plants)
Tomatoes – 15 lbs (standard size – 3 plants)
Cucumbers – 48 (English cucumbers 8-10″ long – 5 plants)
Soybeans – 13 oz (~ 370 gr)
Cauliflowers – 3
Cabbages – 6
Kale – 8 freezer bags
Peas – 8-10 pods/plant (mostly small peas)
Radish – 2 crops
Lettuce – May 25 – July 20 4/5 cuttings per week – October 1 cutting
All in all not too bad for 56 sq.ft but keep in mind that this year was
reserved for testing. Just to find out what’s possible and what doesn’t
work. That means I planted some crops in places where I expected them to
fail – and I was right: some crops didn’t thrive at all, bringing down the
averages. For instance:
The red beets and lettuce were seeded besides tomato plants; as the
tomato plants spread the beets and lettuce stopped growing once the canopy
above them became too dense to let any light through.
– onions and potatoes effectively got finished off by a mid-summer
heat wave. They didn’t die but stopped growing and never really looked
healthy and fresh after that. For the potatoes I more or less expected
this result but I had to put them inside the green house to be able to
plant them early.
-
Peas had similar issues with the heat though they were mostly mature by
then.
Turnips spent most of their energy growing nothing but leaves until
temperatures cooled down in September
The green beans were too close to the water and nearly succumbed to a
fungal outbreak
– growing cabbages indoors is a complete waste of space
Most of the other crops did really well (or better): direct comparisons of
lettuce (before the tomatoes got too big), cauliflower, cabbages
(outdoors) and soybeans suggest yields of 5x to 6x that of same variety
plants in the adjacent garden. That doesn’t mean that the
cabbages/cauliflowers were 5x as big but they grew to normal size heads on
4x area density (1 plant/sq.ft vs 1 plant/4 sq.ft) and took a month less
time to develop.
Soybeans were seeded on the same day in the garden and in the system. The
aquaponics soybeans matured about a month later and yielded some 5.5x as
much per sq.ft as the garden soybeans. For those of you familiar with
soybean yields: due to our short season and low soil temperatures soybeans
will mature but with rather low yields; this year’s garden plot yielded
the equivalent of 25 bu/acre even though they did get fertilized (but at
lower rates then commercial recommendations). The aquaponics bed was
seeded with roughly twice the beans per sq.ft and yielded on average
larger size beans and more pods per plant.
Also of note is the yield of the pole beans; a crop that I cannot grow in
the garden because they usually start to bloom around the time of the
first frost which leaves me with little to show for my efforts.
Cucumbers do a bit better out in the open but yields are quite
unpredictable because the weather needs to cooperate around the time the
plants are maturing. Most years putting 5 plants in the garden will yield
10-12 cucumbers. If I want to count on more I need to start more plants.
This year we had fresh cucumbers for about 6 weeks straight.
So why these big differences? I think there are a number of reasons:
– water is more available to the plants and plentiful (not as much heat
stress)
– nutrients levels in the water are much higher
– related to those: root systems are much smaller requiring fewer
resources to build
– average water temperature was higher than area soil temperatures
Following is a condensed version of the notes I took throughout the season.
Seedlings.
I had some real problems getting seeds of some crops started this spring.
I now believe this was due to the seeds overheating. The top layer of the
gravel beds gets much warmer than the top layer of soil when the sun hits
it. Consequently the worst results came from crops seeded on sunny days.
Seeds germinating in cloudy weather and in shaded areas did much better. I
didn’t actually bother to work smaller seeds into the ‘ground’. They seem
to settle into the spaces between the gravel particles well enough that
they absorb whatever moisture is needed to get started.
Red Beets.
Respectable crop even though even though they were put in the wrong place
at the wrong time. Very sensitive to UV damage if grown under PVC panels.
I will give them a better chance to strut their stuff next year.
Onions.
Grow on coarse bed and limit flooding to avoid constantly wet bulbs. This
leads to mold on outer skins.
Should be planted in outdoor bed preferably facing north.
Radish.
Very easy to grow all season. Can be seeded together with other crops
between the rows since they are ready for harvest in 20-25 days.
Spinach.
Plants bolted into seed before growing their 6th leaf. I may try seeding
them in late August as a fall crop next year.
Cabbage/Cauliflower/Broccoli.
Indoor beds: lots of leaves on long stalks but tiny or no heads.
Outdoor beds: plants develop quickly with normal growth pattern.
Leek.
Grows very fast – just not upright because stems can’t support the weight
of the leaves.
Rutabaga/Turnip.
Lots of leaves all summer but no product. Roots started developing in late
August as weather turned cooler. Will try again in outdoor beds next year.
Potatoes.
Not a lot of potatoes produced mostly due to heat stress. However what I
really wanted to know is if potatoes will grow vertically in layers or
just at the base of the plant. On the internet I have seen a number of
videos from people trying to grow them in enclosures with a small
footprint but plenty of depth. Alas most show people building enclosures
and planting crops but no harvest videos. I did come across a comment that
pointed out this method only works with long season varieties of potatoes.
In effect: use European varieties, not North American varieties. I managed
to source a variety called ‘Bintje’ for my trial and indeed a number of
tubers were growing directly out of the stems about 8 to 10 inches above
the base of the plant. So it seems possible, though I don’t see the
enclosures as a useful solution in my current location because the growing
season is simply too short. I put the left-over seed potatoes in my garden
and got about 4 weeks worth of potatoes out of them. Bintjes are yellow
fleshed and make very good tablestock potatoes.
Tomatoes.
Very heavy feeders. Use lots of water when mature. I figure the 6 tomato
plants consumed about half of all the water that I put into the system for
the entire crop season. They also don’t seem to compete well with other
plants when small; once their root systems develop that disadvantage
disappears. Canopies don’t let any sunlight filter through.
Cucumbers.
Grows along chicken wire and fence wires. Very open canopy: plants growing
underneath didn’t show any problems.
Quick to show Mg deficiency.
Lettuce (leaf type).
Very easy to grow: just put in seeds and wait for plants to grow. I did
get 4-5 cuts from each plant whereas I am lucky to get 2 cuts from plants
growing in the garden.
Peas.
Did okay, but not better than plants in the garden. Like cucumbers its a
good crop to plant along the edge of the beds because peas climb straight
up along a wall and therefore take up very little space in the beds.
Pole beans.
Use climbing supports. Quick to show Mg deficiency. Heat wave was rough on
plants but they adapted in a few days and showed no lasting effects.
I had the plants grow straight up about 20″ and then spread out
horizontally along a panel made of chicken wire. The three plants
completely covered an area of 5 ft by 2 ft with an open canopy: didn’t
seem to adversely effect plants growing underneath it.
Short stemmed green beans.
Yield was about the same we get in the garden. Grown in both indoor and
outdoor beds with similar results though the indoor plants were more
susceptible to disease: a white fungus causing both stems and beans to
rot. Pole beans are much better for this environment.
Soy beans.
Grown outdoors. Did very well. No diseases and excellent yield.
Aquaponics Setup
The heat exchanger panel is made from an old storm window and a piece of
steel siding that I cut to the size of the window frame. The front of the
steel was painted matte black and against its back I fastened a piece of
1″ thick styrofoam. In between the window glass and the steel plates I put
three pieces of black painted 1/2″ copper pipe in parallel and running the
length of the window. Tees and elbows connect these pipes to headers and
water is pumped through them. This setup works surprisingly well and has
no problems raising the system’s water temperature into the 70s for most
of the season. Water is pumped directly from the collection tank into the
panel and the return line goes back into the collection tank. I am using a
low volume (8 lpm / 125 gph) pump with the panel so pressure and energy
use will stay low. Still this pump consumes more energy than the flood
pump because it runs continually. For this reason the pump is only allowed
to run if battery voltage is 12.6V or higher. The panel is also outfitted
with a temperature sensor between the steel siding and the window. Its
highest reading this summer was 90C (~195F).
– The water temperature in the system closely tracked our soil
temperatures. Though the heat exchanger would raise water temperature
during the day, by the next morning it would drop again to around 60F in
mid summer and lower in spring and fall. This could be due to the fact
that the collection tank resides underground with just its top showing
above ground. To curb heat losses I have dug up the tank this fall after
the system was shut down and have insulated it with 1″ thick styrofoam
strips that were glued to the tank with polyurethane insulation foam. So
next year I will find out if underground heat loss was really the culprit
or that most losses come from low overnight air temperatures.
– One thing about putting the tank underground (and painting its top
black) is that it completely eliminates algae growth in the tank.
If possible put photovoltaic panel and heat exchanger panel on south
side [in the Northern Hemisphere.] It is important that they can be turned to the sun early in the
morning because in spring/fall there is less cloud cover at that time of
the day.
– Ideal slope of growth beds is slightly away from drainage hole to keep
some extra water in the bed.
– When using a 55 US gallon collection tank, the system should include no
more than 16 beds to avoid running the pumps dry in hot weather when the
most water is used. Max water use is around 10 seconds pump time per bed.
– The greenhouse is made of PVC sheets which seem to block all UV light,
leaving the plants without any protection if the sun’s rays happen to hit
them. Exposure to the sun for about half an hour was enough to discolor
leaves from green to yellowish green and stunt growth for approx. 4 weeks.
The same thing happened to plants that I started indoors once they got
transplanted outdoors. I have never seen this happen when starting plants
behind glass. Some crops seem to be more susceptible than others and the
problem can be avoided by exposing plants to direct sunlight for 15-30
minutes per day from the time they are seedlings.
– Water pumps should be reliable. My main flood pump is a 12V bilge pump
(1000 GPH) that has worked without a single glitch for 2 seasons now but I
do have a backup pump on hand. Finding a low volume circulation pump for
the heat exchanger has been more problematic as the cheaper pumps
generally lasted only 6 weeks before gumming up / seizing up / burning up.
I have settled on a soft start pump which has been up to the task for the
second half of the season. As an added bonus the pump has built-in
overload and dry-run protection.
- Underwater electrical connections need special attention because the
growing solution is salty and slightly acidic and therefore very corrosive
on solder joints. I found two approaches that work for more than a few
weeks.
A) pack the connection in a gasket forming material, slide heat shrink
tubing over the connection and shrink it to create a very tight gasket
around the wires.
B) take a few inches of 1/4″ copper tubing and squeeze it shut on one
end. Put a few drops of molten wax or paraffin in the tube. Put your
connection into the tube and fill it to overflowing with more molten
wax. Let the wax solidify and put a piece of heat shrink tubing over the
open end of the tube to protect the wax from mechanical damage. This
approach works really well for sealing sensors.
Watering the plants.
There are two important variables in an ebb and flow system. The quantity of
water pumped into the beds each cycle and the time between floodings. The
term ‘flooding’ should not be read as having water run over the growth
medium. Plant roots are designed for moist environments – plant leaves and
stems not so much. I set the valves and pump times so that you could just
see the water rise between the pebbles at the time the pump shut off and
this works very well. To automate the task one of the beds is outfitted
with a float sensor which opens when the desired water level is reached.
Early season cycling (=time between floods) can be as long as three hours
because seedlings do not seem to care for being flooded often and there
will be plenty of moisture for them in the beds. Decrease cycle length to
70-90 minutes when plants start to grow. For mature plants use 30-45
minute base cycle. During cool weather (60F) the base cycle is
automatically doubled. In warm weather (heat exchanger temp. 90F) the
cycle time was reduced to 20 minutes. In hot weather (heat exchanger temp.
110F) the amount of water pumped into the beds was increased by 25-30% to
make sure the beds won’t be sucked dry before the next cycle starts. If
too much water gets pumped into the beds, the float sensor automatically
shortens the next pump time to avoid overflows.
At the onset of hot weather it is important to cover the roof with tarp to
avoid overheating of plants because they are not yet used to high
temperatures. It seems to take only 2-3 days for them to adjust though.
Also provide for plenty of air circulation.
Warm weather night time cycle was set to 1 hour otherwise beds can be
sucked dry through evaporation causing plant wilting. Cool weather (50F)
night time cycles can be as long as 3 hours without measurable adverse
effects.
As you may understand from the above, my goal is to pump as little water
as possible without adversely impacting the crops. This is the key to low
energy usage. Photovoltaics is an ideal fit to power the system because
you need to pump lots of water on a hot summer day when the panel produces
the most energy anyway. But on cold and dreary days the plants don’t seem
to be too interested in getting wet every 20 minutes.
It would be quite a chore to make so many adjustments but fortunately we
have micro-controllers to do the dirty work. My current controller has a
light sensor and a temperature sensor in the heat exchanger. From their
readings it can figure out day/night and the type of weather. It adjusts
the cycle times accordingly.
To complete the picture: the controller uses the float sensor in the
growth bed to check the main pump’s operation and a water temperature
sensor in the collection tank to run the heat exchanger pump. The
photo-voltaic panel and battery are also actively managed (through a
voltage sensor) to safeguard the crop as much as possible. And if any of
the system’s operating parameters goes out of bounds, the controller
sounds the alarm which is rather re-assuring.
Now, don’t get me wrong: I understand the risks in going hi-tech. But the
system can still run fine off a basic timer for the flood pump; its
performance just won’t be as optimized.
For most of the season I used rain water collected from the roof of the
greenhouse as feedstock for the system. The water was collected into an
old trashcan, tested and pumped into holding tanks if approved. Rain water
quality was good most of the year. Total Dissolved Solids (TDS) levels approached those of
de-ionized water (10 ppm) and only once (end of June) did a cold front
deliver elevated radiation levels. At twice background radiation it wasn’t
anything to worry about but I had plenty of water on hand so this got
dumped.
Fertilizing.
Plants need minerals to grow and the bulk of phosphorus and potassium came
from 10-10-10 commercial fertilizer. Additional quantities would have come
from the manure tea I used but how much is hard to quantify. 10-10-10
fertilizer was added by dissolving 3 handfuls in a pail of water and
adding the solution to the collection tank. This was done once or twice a
week as needed. Total quantity used for the season was about 10 lbs.
As the plants got larger extra nitrogen was added in the form of 30-0-2
(golf green) – total quantity for the season about 3-4 lbs.
Since the system was started with plain tap water, I raised the fertilizer
levels in the course of a few weeks to make sure the young plants’ roots
wouldn’t get burned. Although a gradual rise is necessary when plants are
used to low fertilizer concentration, it is quite a different story for
seeds. In early August I put lettuce, radish and kale seeds in the beds
while the system’s TDS level was around 5000 ppm. Within 24 hours all of
the seeds started pushing out their roots into the gravel and never looked
back. Germination percentages were excellent.
This is all the more remarkable for lettuce which (according to commercial
literature) has an upper limit of 800 ppm for fertilizer solutions.
However in commercial operations lettuce is usually grown in beds floating
on the fertilizer solution and its roots would be in constant contact with
the water. I have to assume that ebb and flow systems work very
differently from a plant’s perspective because I have seen spikes up to
6500 ppm and the lettuce was growing very fast instead of dying off.
I was shooting for a fertilizer solution strength of around 4000-5000 ppm
for most of the season. This worked well enough until the middle of July when I
started to see strange readings to the point that I thought my TDS meter
was broken. After a few days of more frequent testing I started to see the
pattern: very high readings at sunrise that kept dropping throughout the
day. For example 6470 ppm at sunrise – 5250 ppm around 9 AM – 4450 ppm
at 7PM. Then it dawned on me that I had 2 beds of beans in the system,
hosting lots of bacteria that were very busy fixing nitrogen and releasing
nitrates into the water. To give you an idea of how much nitrate was added
by the bacteria: if I dissolved 3 handfuls of golf green fertilizer
(almost pure ammonium nitrate) in a pail and added them to the system, it
would raise ppm readings by around 675-700 ppm.
The large nitrate releases happened until the end of August, after which
they started to get smaller (around 200 ppm swings by early October). The
main thing is that the bacteria like warm water (70-75F); if the water
temperature stays below that they work a lot slower.
Needless to say that some of the crops really took off at that time with
tomatoes and cucumbers the biggest beneficiaries. This also resolved one
of my biggest concerns: in case commercial fertilizer becomes unavailable,
using manure tea will work fine for phosphorus, potassium and most other
required elements but dry manure is very deficient in nitrogen; the very
element that regulates plant growth. You could use fresh liquid manure
which still retains a large portion of its nitrogen but that is rather
messy. Instead I will just plant more beans!
Tomatoes and cucumbers showed signs of magnesium deficiency early on so
this element was added to the solution from time to time and no more
problems were encountered. A good source of magnesium (and sulphur) is
Epsom salts (MgSO4.) Kelp extract and ocean salt were added to provide
some additional trace elements, however I have no way of knowing if the
system would have been deficient without the additions.
If you are interested in how well balanced your plants diet is, you should
get a piece of software called Hydrobuddy. Its free to download and comes
with its own database of plant nutrient requirements for many crops and
chemical analysis of a lot of commercially available fertilizers. You can
also add your own concoctions to the database provided you have some idea
of their chemical analysis. You can tell the program how much fertilizer,
manure, blood meal, etc. you use on which crop and it will tell you how
well balanced your crop’s diet is on all important nutrients and trace
elements.
And don’t forget to get your own TDS meter while
you are at it. They sell for about $8 and are worth every penny if you
want to get a feel for what is going on. Another thing I should mention in
case you haven’t already done so: it is still very easy to find good
pictures of nutrient deficiencies and diseases in crops on the internet.
You probably should download some for future reference.
Corn trial.
I also tried growing several varieties of flour corn in the garden this
year. Only the short season varieties properly matured – no surprise
there. But I will highlight 2 varieties that stood out.
Bloody butcher was the only variety that withstood high wind gusts without
needing additional support (i.e. getting blown over). However its
borderline feasible at this location as it barely reached maturity and
that only thanks to warm fall weather.
Mandan Red Clay stood out in two ways: the plants looked miserable all
summer, barely growing to 3 ft high with lots of tillering. Nevertheless
they managed to grow 6″-8″ cobs with 8 rows of large kernels that fully
matured. That produces a well above average yield-to-total-biomass ratio
which may come in handy some day. Red Clay does not like cramped quarters;
in narrowly spaced rows a high percentage of plants did not grow any cobs.
Next year’s plans.
With blind testing out of the way, next year’s plans are taking shape.
First up is to try to get the system up and running around April 1. Inside
the greenhouse I will focus on growing leafy vegetables like broadleaf
lettuce, swiss chard, endive and purslane. Radish and cucumbers will also
be grown inside and I would like to try some pepper plants just to see
what happens. Onions, turnips and red beets will move to the outdoor beds.
I also plan to add 4 more outdoor beds that are spaced farther apart then
the current beds. This is not a problem: I just need to add a few extra
yards of polyethylene pipe between them. The reason for this is that I
think I can grow a 10ft x 12ft patch of pole beans over top of a single
bed. I could let the beans grow vertically but the terrain is rather open
and susceptible to wind gusts so I prefer low to the ground solutions. The
same is true for my tomatoes and cucumbers, though I know the plants are
willing climbers.
Pole beans and cucumbers happily grow along some baler twine, but for
tomatoes I prefer something more solid like chicken wire or lattice to
cope with the weight of the growing fruits. Its not that your baler twine
breaks but it will cut through the stems.
Tomatoes may get their own bed or I can take a panel from the side of the
greenhouse and simply let them grow ‘through the wall’. One of the nice
things about a aquaponics system is that you don’t have to worry about
crop rotation so I can select the bed that is most suitably located for a
specific crop and build the required infrastructure around the bed without
having to change it each year.
I also plan to add strawberries to the mix. The plan is to grow them in 5″
flower ports that are located in a piece of eaves-through where the water
flows through. The eaves-through will be suspended about 18″ above the
existing beds. Of course I have to get the plants through the winter
first: most of them are currently located in a hole in the ground that is
covered with clear plastic and snow, so we’ll see how many survive.
And finally I would like to put in a good word for our pollinators. You
are probably aware that they, too, are having a tough time surviving. Not
just commercial hives but the wild ones as well. For any open pollinated
crop that starts out with flowers, you really need them if you want to see
any harvest at all. And so there are some things you want to do that are
good for both your local pollinators and your crops.
– Help out the pollinators by growing nectar producing flowers in the
vicinity of your vegetable garden.
– Make sure that local pollinators put your garden on their map early.
– Avoid use of hazardous chemicals on your veggies as much as possible.
There is quite a bit of information available on what plants attract
pollinators but most of those plants are annuals (at least in this neck of
the woods) that bloom rather late in the season. Which is no doubt helpful
but I want flowers that bloom before my crops. That way pollinators will
know where to come looking when I need them. There are plants that bloom
early and that seem to provide lots of food. We have two of them around
here that are not very common but work out really well.
One is a small plant called a grape hyacinth. Its lavender colored flowers
look like a bunch of tiny grapes growing upside-down. Time wise it blooms
between crocuses and tulips, anywhere from 5 to 14 days depending on
temperatures. That is just the time bees and other insects emerge from
their winter quarters and they really appreciate some fresh food. These
plants require no special care but you have to let the foliage die
naturally in summer if you want the bulbs to grow and multiply. Replant
the bulbs every third year to avoid overcrowding as they grow few flowers
in that situation.
The second one is called Angel Wings (Rosa chinensis). These are miniature
roses that start flowering late May/early June and for a few days make
your garden smell like a rose garden. They continue flowering into fall
with ups-and-downs depending on the prevailing weather. Pollinators are
strongly attracted to these plants: you can hear the buzz when walking
past the garden. Unlike real roses the plants are disease resistant,
carefree (except for yearly pruning of dead wood with leather gloves) and
very hardy: ours have survived -10F without protective cover on multiple occasions.
Article source: http://www.survivalblog.com/2014/01/aquaponics-an-update-by-dp.html