Last year we tried a DIY
Sub Irrigation Planter (SIP) for the first time. A SIP is a planter system
where water is introduced from the bottom of the planter. This allows plants to
have a constant source of water, and also saves you, the gardener, from having
to water as often. We have an upper deck that gets pretty good light and were
interested in a having a few container plants. We had tried cherry tomatoes in
the past, but had issues with them splitting in the heat. Especially in the
middle of the summer, we’d water the plant in the morning, and by the time we
got home from work the soil was completely dried out. This also made it hard to
leave for more than a few days, and we didn’t want to be reliant on friends
coming by to water for us.
We got a book from Jesse’s brother called Fresh Food From Small Spaces, and this is where we first learned about SIP container
gardening. We were intrigued, and Jesse did lots more internet research (he
loves to research things) to learn more about how we could apply this ourselves
(this is a pretty good site to learn more). You can purchase SIP containers
read to go, but I wanted something that was a little more aesthetically
pleasing than what is out in the market, and we already had two tall planters
my mom had gifted to us (and I really like overcomplicating things). We tried this for the first time last year, and it
worked out pretty well. We had more success with the cherry tomatoes than the
bell peppers, but that could be for a variety of reasons.
Our planters worked
out great to convert to a SIP. The extra height allows enough room in the base
for the water reservoir. Dimensions will vary depending on the planter you use,
but as a reference, here is what we were working with. Tulip planter (widens at
the top): 20”tall, 14” diameter at the top, 9.5” diameter at the base. 2 gallon
bucket: 9” tall, 9”diameter.
Planter, bucket/container for the water reservoir,
PVC pipe for the fill tube, plastic water bottle for the soil wick,
plywood/wood/bucket lid for the platform, landscaping cloth (not mandatory),
and a mason jar to fit over the fill tube opening.
1. Find an appropriate planter (my mom purchased ours from
Piney Ridge in Johnston, Iowa).
2. Find a bucket/container (the water reservoir)
that fits snugly into the bottom of the planter. It still needs to have a
little extra space on the sides, so when the reservoir becomes full*, the extra
water will spill over the edges, and out the bottom of the planter. Our bucket
is made of HDPE (high-density polyethylene) food grade plastic.
*If you can/want to drill holes into your planter, you can
drill drainage holes near the top of the water reservoir, and this will allow
the extra water to flow out through the openings.
3. The platform piece should
fit on top of the bucket/container. We used untreated plywood*. The platform is
the same diameter as the bucket. You will need to cut two holes, one the
diameter of the water bottle you will use for the wick (placed in the middle),
and a smaller hole that is the diameter of the fill tube (off to the side).
*We may try finding a bucket with a lid next
year, and using the lid as the platform. This may be more efficient than what
we currently have.
4. We purchased a large bottled water to use for the wick
(the extra large size). Jesse cut the top off, and drilled several holes into
the plastic. It wasn’t quite tall enough to touch the bottom (it should be
slightly taller than the bucket), so he added a few pieces of leftover plywood
to the bottom. Gradually fill plastic bottle with soil, watering the soil and
compacting down the soil as you add more so it is very dense.
5. Place wick in
center hole, make sure top is flush with the platform.
6. Cut the bottom of the
PVC pipe (fill tube) at an angle to ensure the water can flow into the bucket.
Add fill tube through smaller hole in platform.
7. Add landscaping fabric*. You
won’t need much landscaping fabric, so we asked some friends who were
homeowners, and one had lots of extra that he was happy to pass onto us. You
can adjust the fabric as you add the soil. If you can, try to keep the fabric
above the soil line.
*Not mandatory, but can prevent roots from getting into the
water reservoir. We used landscaping fabric last year, and the bell pepper
roots still made it around the landscaping fabric and started down the side of
the fill tube. I don’t think this affected the peppers at all though.
9. Place plant into dirt. Place a cover over the fill tube when not
in use. A mason jar works well. This does a couple things; it keeps mosquitoes
from going into the tube and laying their eggs in the water, and also keeps
other stuff from clogging up the tube.
Depending on how much rain
you have, and how hot it is will effect how often you need to water. If the
dirt is dry, I like to start by watering from the top, so the plant and top
soil are wet. Than we fill up the reservoir by pouring water into the fill
tube. We continue to fill it with water until we see water pool up in the tray
on the bottom. Since we have a 2 gallon container, we also know roughly how
much will fill it up (this also allows us to see how much water was soaked up
within a period of time). A gallon milk jug works well for this part, since it
also lets you measure and track how much you have put in.
We’ve figured out a
water management system, but now need a pest control system. We made it about
half way through last season before the squirrels found our tomatoes (they left
the pepper and other plants alone). They have already found the plant this
year, and started to eat the leaves of the tomato plant! It really pisses me
off, and we are working on a system to keep them out of it. We are trying bird
netting, but haven’t quite figured out the logistics yet. If you have any
suggestions, let me know!