High Production Container Gardening in a Small Space Using Sub-Irrigation Planters (SIPs)

We live in an older house on a larger city lot, with a shady back yard and a small sunny front yard, so we struggle with limited space for a vegetable garden, like many people do. To work around these factors, we use a sub irrigation method of gardening that allows us to do high production container gardening on our asphalt driveway. 

We have found this approach to be very flexible and accommodates our lifestyle and gardening goals.



Sub-Irrigation Planter Box

Using a Do-It-Yourself sub-irrigation approach, we make our own closed system planters. These are large plastic storage totes that we modify to add a raised floor with a 5 gallon water reservoir in the bottom and an overflow vent.

The plants water themselves as needed though water wicking. This approach makes it easy to water your garden, use water efficiently and not have to worry about under or overwatering.

I'll make a page that shows how to make these planters in a future post.




Vegetable boxes kept under cover in a warm place


Once the planters are up and going, they are very low maintenance and completely portable, so they can be moved in and out of a greenhouse for extended growing. 


This is also a great way to start a garden in a limited space or in cases when you are unsure about where the final garden location will be. 





We start our boxes in a greenhouse as early as February.  The boxes are kept in a group in a warm area until late spring.
 

This set of boxes contain lettuce and peas. We started them early and set them out under a plastic cover to create cold frames. This helps get a jump on the growing season.

SIPs in the driveway

We move the boxes out into the driveway once it is warmer. In this case, we started out by tucking our SIP boxes against the retaining wall at the side of our driveway, where it is very warm and sunny.




Tomatoes grown over a arbor gate

We grow all kinds of vegetables in these systems, including corn - which gets quite big and loves to suck up water.




Tomatoes also get big and consume alot of water, so we grow two plants in each box to control the crowding problem that occurs over the summer.  Very large tomatoes are trained to an arbor gate to support the weight of the plants, improve airflow and make it easy to harvest as they ripen. 







We bring in a steady flow of tomatoes (and everything else) from late summer until frost, when we clear the vines and have alot of green tomatoes.








Watermelon Trellis

Cucumbers, watermelon and peas are grown vertically on trellises.  We like to grow Tiger Baby watermelons because they stay small and we can suspend/support them in little slings from the trellis.


 

Assorted Peppers

We reuse the soil each year, but practice 'crop rotation' in a way that rejuvenates soil (last year corn, this year beans, etc).  Except for the asparagus, it stays put permanently. 



We augment the soil each spring with compost, lime with magnesium and a fertilizer.  We typically grow all the normal vegetables that you'd expect in a garden.






Apple Tree in a pot


We also use this approach for our fruit trees, though we actually use a combination of three techniques - bonsai, espalier and sub irrigation.

The fruit trees are started in 24" pots and grown for 2 - 3 years until they are ready to go into the larger sub irrigation planters (it is easier to move the trees around and find where they do best in the smaller planters). These fruit trees are semi-dwarf and root trimmed every third year.

Tree with Espalier

After they have grown branches that are long enough to train - generally on their third year - we build a bamboo "table espalier" about 5' above the tree and train the branches to the trellis.


The overhead trellis achieves many things at the same time - it supports the weight of the fruit and protects the branches from breakage, it provides good air circulation which reduces disease and fungus, it makes the fruit easy to harvest and the tree is easy to prune and check for bugs or other health issues.



We grow quince, apples, pears, cherry, peach, and nectarine this way.  We also grow hazelnuts in containers using the bonsai method.





There is a specific approach to fertilizer when growing fruit trees in a container/bonsai approach.  You use a different NPK ratio than normal and you add it a lot more frequently.  I'll go into that in more detail in a future post.





Heronswood Visit

May 18th was a wonderful day.  Heronswood was open to the public for the first time in over 6 years.  

Heronswood is one of those wonderful places that have specialty gardens featuring rare plants and a shade garden that crawls around the woodland floor and shows you what you can do with shade, when given a chance and an adventurous heart.

The Grotto at Heronswood

 

I was delighted and we made the hour and a half drive up to Bainbridge Island extra early that Saturday.  Not only was the garden open, but there was a big plant sale with all my favorite rare plant dealers attending, which meant there was a good chance I could pick up a couple of the items I need to round out the shade garden here.

First thing when we got there - Shopping!!  It didn't take long before I rounded up a beautiful Podophyllum delavayii and a hexandrum for my growing "podo" collection, as well as a couple different Diphylleia grayi and an extra bronze Rodgersia.  After quite a bit of back and forth, I took the plunge and bought an arisaema tortuosum - a 'jack in the pulpit' that could easily get 5' tall, which is why I've held off for so long.  (I have several jacks of assorted type, so it really wasn't that much of a stretch for me).

Paris thibetica

 

I kept eyeing (and finally caved in and bought) a beautiful Paris thibetica from Windcliff/Dan Hinkley.  If you've ever been 'on the fence' about buying a rare new plant, I can tell you that asking one of the country's most highly respected plant collectors his opinion on it is a sure way to guarantee you buy the plant - which is exactly what I did.  

 

 

Columns in the forest

 

After we finished our shopping, we put the plants in the car and headed into the woodlands of Heronswood.  I knew I was in the right place when we quickly came across a mythical looking collection of columns standing quietly among the darmara peltata, rogersia and podophyllums.  It was so unexpected and yet so natural there.

Back Yard

After a long stroll through the woodlands we arrived at the original house and the gardens surrounding it.  Each area was done in different garden styles and was amazing, even as it is in the process of being restored by the Port Gamble S'Klallum tribe and Dan Hinkley.

 

 

 

 

 

Formal Garden

 

 

 

The Formal Garden was just starting to sprout and the bright green boxwood pattern stood out strongly against the surrounding trees.  It would be great to come back here later in summer and see how it has changed.

 

 

 

 

 

 

One of the coolest garden was this huge roman arches made from carefully clipped trees that had been planted very closely together.  When you get up close to this room, you can see that the entire structure is strictly trees, no fencing or physical structure has been added to this.  Inside the garden there is a smaller knot garden.

Roman Arches

 

Driveway / Entryway

 

 After leaving the room of arches, you walk out the back and to the driveway that approaches the back of the house.  This large bed served as a strong focal point before your eye is drawn to the green arches of the room behind it.

 

 

 

 

Driveway Border

 

 

On the way back up the drive there is a long rectangular garden and a row of hedges creating a clear separation between the wild forest and the structure of the formal gardens.






 Peony Tree

On the other side of the road is a very large peony tree that had just finished blooming.  I'm not sure which made me more jealous - the huge peony tree or the large batch of darmara peltata growing next to it. 


From this point we wandered back into the woodlands and up to the Grotto before making our way through the wonderous forest to the old nursery space and plant sale.




If you've never been to Heronswood before, you owe it to yourself to go if the opportunity presents itself. 



Hostas - a good start



Before



Our garden has come a long way.  When we first bought the house, the shady border around the yard was covered in bark mulch and nothing else.   It had been used as play areas for the previous owner's children and it looked like it.  We really were starting with nothing but bare shady areas and not what I would consider the best soil.

 

After





I didn't realize that we actually had nice woodland soil that was good for shade plants, it just needed a little perk-up.  The ground drained quickly, it had a good mix of fir needle duff and dark soil and the shade changed and shifted depending on the time of day.  All it really needed was regular water, some compost and a little work to turn it into a lush shade garden.



Giant Hostas

  

Back then I was pretty new at shade gardening and I asked myself the question everyone does when faced with a wall of shade - what do I do with this???  And what was the answer??  Hostas!!!  Yep, I bought some hostas - ok, so I bought a lot of hostas.  And not just the small ones, I got some of the young giant ones and hoped they'd grow into massive plants some day, which they gradually did. 



Note to readers - if the tag says the hosta is a giant, believe the label. Some hostas  get huge.

  



I know...everyone starts with hostas and people often roll their eyes and say "hostas are boring" but they are great anchor plants in a shade garden - and a good beginner plant when learning to grow in the shade.  They are reliable, easy to grow, forgive your mistakes, are tolerant of deep shade as well as bright shade and they'll let move them around later on (if you can get them out of the ground).  Seriously, hostas are very hard to kill, as long as you keep them in the shade.



Hostas make a great backdrop for unique plants or yard art.  I use the heart shaped leaves of hostas to create the green background that show off my spiky lime green grasses or rectangular podophyllums.  Even a wave of impatiens look impressive against the smooth green of background hostas.  When I need a little height, I put them in a pot and put other plants in front of the pot - it's a form of cheating, but it works great in the garden. 



So how do you keep hostas?  You can plant them in the shade and let them be.  Really, you can.  If you want them to grow big, then water them regularly, give them some compost in the early spring (Feb/March here) and fertilize them with 16-16-16 in early spring and August.   

Tibetan Poppies



Balloon Dogs running through Black Mondo Grass

So I've decided to start a gardening blog.  It seems I have several gardening tricks that are successful enough that friends and family are asking for them - and a blog seemed like a good way to share that information.  We'll see how it goes. 

Right now things are huge and a little out of control in the garden, but I'll get to that a little later. 


As usual, our spring/summer lurches along with some cold wet days and some cool cloudy dry days...followed by a warm sunny day that causes everything to grow frantically.  I find this pattern erratic and the effects hard to predict, but the plants seem to love it.




Tibetan Blue Poppy



 

Though our few sun loving plants are slow growing this year, our shade loving Tibetan Blue Poppies (Meconopsis betonicifolia) are up and flowering.  They get enough morning sun to make them happy, while protecting them from the 'real' sunshine during the day - when we get a full day of sunshine, that is.

Our Himalayan Blue Poppies (Meconopsis 'Lingholm') are not old enough to flower yet, so we wait and watch as they grow - maybe next year.