Sub-Irrigated Planter (SIP) Workshops in Chicago

We're delighted to be teaming up with Nance Klehm's Spontaneous Vegetation to offer two practical workshops on making two-bucket SIPs.

They are scheduled for Wednesday May 20 (6-8 pm) and Saturday May 30 (1-3 pm).


You’ll go home with:

A ready to plant two-bucket sub-irrigated planter (SIP). Our experience has shown that it will produce, on average, 25 lbs of tomatoes during a growing season.

Enough potting mix, organic fertilizer, and powdered lime to plant your tomato.

An organic heirloom tomato plant, from the Green Roof Growers seed-starting group.

A comprehensive understanding of how SIPs work and how to put yours to work once you get home.

Where - Wicker Park, near Division and Leavitt
Specific directions given upon confirmed reservations.
When - Wed., May 20th (6-8 pm) and Sat., May 30th (1-3 pm)
Cost - $50
Register with Nance by email - nettlesting@yahoo.com
Click on her site and scroll down a page for more details.

Co-teaching with Bruce and H2 will be LA's favorite homesteader Erik Knutzen of Homegrown Evolution and co-author, with his wife Kelly Coyne, of The Urban Homestead. Autographed copies will be for sale and we'll be giving away a copy or two as well.

Hope to see you in May...

[Updated 5.21.09, Check out our Recap of the May 20th workshop]

Three-Season Growing in Chicago: First Harvest of 2009

Here's an idea for anyone who yearns to start growing food before the ground can be worked in March.

We've harvested four big bowls of cool-weather greens in the last couple weeks. With Chicago's temperatures swinging wildly between 80 and 40 F, the greens alternate between getting a shot of growth-spurring heat and the cold they thrive in.

This picture was made April 26 (the SIPs look a little light since I've started regularly cutting for meals). Greens deliver near-instant gratification. When you plant a tomato, it's an act of faith that two to three months later you'll be reveling in flavor.

The Red Velvet lettuce from Seed Savers below is just coming into its own. I wonder if it will ultimately produce the very dark red lettuce shown at the link.

It's a thrill to stop buying organic greens shipped in from California (though we're lucky to have access) and instead tuck into a bowl of 12 different chards, kales, lettuces, mustard, arugula, and cress, chopped and doused with the house dressing: olive oil/Dijon/chardonnay. These young greens are so tender they don't need steaming.
We're lucky that Bruce started our cool-weather plants under lights, so they'd settle in and start producing quickly. The direct-seeded versions in our tiny in-ground garden bed are lagging behind a bit.

It's worth noting that anyone who wants to try growing in SIPs, including earthboxes, can start these beauties from seed inside in February before planting and setting them out in late March/early April. In Chicago, this extends our growing season by at least 6 weeks and generates a steady supply of phenomenal green food.

Next year I think we'll try starting even earlier...

Extending the Chicago growing season

Lots of good news from the roof on this grey Chicago day. First, our relationship survived assembling the birthday gift greenhouse. Even better, it's been an extraordinary tool for planting our bucket SIPs early in the growing season. These pictures are from the first ten days in April.

(Pause to thank Bruce for nurturing the cool-weather plant starts to robust health in time to get them in early.)


This view is from inside the rooftop greenhouse, where I planted our SIPs. Getting the organic fertilizer in a ring around the top of the soil and then the plastic over the top is challenging in any kind of wind. The greenhouse (or any shelter) lets you to accomplish planting without fighting a breeze.


Here, Mr H2 is madly making deckways all over the roof so we don't wear it out. I can't get him to come downstairs.


This is the new run of SIPs, already set up and planted (in the greenhouse) with cool-weather greens like collards, kale, broccoli, and spinach and then hardened off before moving outside. The plants look a little beat-up because they're just settling in.


'Champion' Collards in situ...


The big view--we've expanded a little each year.


But remember: growing organic food on your balcony or roof, in your yard or the vacant lot next door requires just a little initiative and a couple of buckets, totes, or an Earthbox. A sunny location is essential. Then just keep the water reservoir full. You won't believe how much high-quality food you can grow.

Housekeeping

Sorry about the Twitter feed/RSS overload.

I hit the wrong button. It should be back to normal now.

Off Topic

I'm hijacking the eyeballs of our readers to ask anyone looking to rent a 2 BR garden apartment in Chicago's Wicker Park neighborhood to click on this.

Who knows? It might work.

[updated 4/13: Thanks to all who responded, it's rented.]

Making a 10-10-10 Organic Fertilizer

As I said in a comment to H2 in the previous post on Blending Fertilizer, the way Science--in the guise of N-P-K numbers--looks down at gardening is a problem. My hope is that by talking about how these formulas are put together some of their (undeserved) power will fade.

The reason for this post is that I want an inexpensive basic 10-10-10 slow release organic fertilizer, and I can't find any. Maybe for good reason, I don't really know. I do have the components, courtesy of a clearance sale at a local garden store, to make my own blend.

*******5.22.10 - I've since found out that the ideal ratio for NPK is 3:1:2.

3:1:2 ratio fertilizers don't supply 'excessive' N. Plants use about 6 times more N than P, so 1:1:1 ratio fertilizers actually supply far more (excessive) P than plants can use in relation to N. The 15-30-15 you suggest actually supplies 12x as much P as plants can use in relation to N, unnecessarily raises the electrical conductivity and level of total dissolved solids of/in the soil, unnecessarily raises pH, and makes it more difficult for plants to absorb water and the nutrients dissolved in water - particularly Fe and Mn.

This post is still useful. I'll use the same methodology to make a 9-3-6 fertilizer.*******

Here's how I do it.

Home gardeners and their suppliers are trained to think of volume, not weight, when it comes to fertilizer, i.e. 3 cups of 10-10-10 fertilizer per Earthbox™/18 gallon SIP. Farmers and Growers measure fertilizer by the weight of the available (to the plants) N-P-K, expressed as a percentage of the total weight of the fertilizer. Those are the 3 numbers you'll find on the back of all fertilizer bags. So to come up with a blend, you'll need to use weight to make a batch with the proper proportions and then measure out the amount to use from your blend by volume (in cups).

My goal is a 10-10-10 fertilizer. Meaning 1 pound* of fertilizer with .10 lb of N available, .10 lb of P, and .10 lb of K. The basic math can be used to create any mix you'd like.

* Chemistry can be very precise. The way it plays with the meaning of words is confusing as hell. Remember that 1 lb of delivered NPK rated 10-10-10--expressed as a percentage of the total weight and available to be used by the plants--will weigh more than 1 pound. We're determining the weight of the available NPK, not the total weight of the blend.

I have Miracle-Gro Organic 7-1-2, Espoma Triple Phosphorus 0-46-0, and Espoma Epsom Plus 0-0-22. Following the basic formulas laid out at this site, it's possible to combine these into a 10-10-10.

You can skip down to the end if you want the answer. In the meantime, I'm going to show my work.

The numbers behind the making of 10-10-10.

To simplify(!) the math, I'm basing this all on 1 pound of fertilizer.

Start with the most complete element, the 7-1-2. It provides .07 lb of N per 1 pound of fertilizer. To get .10 lbs of N, I'll need .10/.07= 1.43 lbs of 7-1-2.

In that 1.43 lbs of 7-1-2 there is 1% of P or .01 x 1.43=.0143 lbs available. We need to credit ourselves for the P supplied in the 7-1-2, 1%, so we subtract .0143 lbs from the .10 lbs required, leaving a deficit of .0857 lbs to be made up using 0-46-0. We divide the .0857 lbs needed by 46%, or .46, to get .186 lbs. That is the amount of 0-46-0 we need to add to our blend to get .10 lb of P available.

Finally we need to account for the K supplied by the 7-1-2. In the 1.43 lb of 7-1-2 there is 2% of K or 1.43 x .02= .0286 lbs. Subtracting that from the .10 lb of K needed leaves a deficit of .0714 lbs to be made up by the 0-0-22. So divide .0714 by .22 to get .323 lbs of 0-0-22 necessary to make .10 lbs of K available to the plants.

Now we have the formula for 10-10-10, delivering 1 lb of N-P-K:

1.43 lbs of 7-1-2
.186 lbs of 0-46-0
.323 lbs of 0-0-22

To use this formula I converted lbs to grams by multiplying each of the amounts by 454. (454 grams = 1 lb). This let me easily weigh them on my kitchen scale, which I enclosed in a zip-lock bag to keep it clean.

I weighed each component separately, adding to a bucket as I went along. As I was measuring them, I made a point of weighing 1 cup of each. This way I can recreate the recipe with a cup instead of a scale.

One cup of 7-1-2 weighs 165 grams
One cup of 0-46-0 weighs 320 grams
One cup of 0-0-22 weighs 390 grams


The Simple Answer

To make a little more than 4.5 cups of 10-10-10

4 cups of 7-1-2
.25 cup of 0-46-0
.375 (3/8ths) cup of 0-0-22

To make 22 cups of 10-10-10.

19 cups of 7-1-2
1.25 cups of 0-46-0
1.80 cups of 0-0-22

Because of rounding errors, i.e. I turned 3.93 cups into 4, the amounts don't scale exactly. You can vary the quantity. Just keep the ratios between them the same.


Each of my thirty SIPs needs 3 cups of 10-10-10, so I'll be making this a few more times this spring.

Making a Custom Fertilizer Blend

[Newer post with an easier to use formula, here.]

Fertilizer has been a sticking point for a while. I could never shake the suspicion that all the talk online, and from Official Garden people, never really explained what those numbers meant. More to the point, how do I combine them to get what I want--which method do I use? Do I just add the numbers together? I managed to pass a chemistry class in college--a while ago--why can't I figure this out!?

I get the basics. N-P-K + vital nutrients; 3 cups of organic or 2 cups of petro-chem slow release fertilizer rated between 5-5-5 and 15-15-15. Blah, blah, blah. And it's not just N-P-K that's important. Ideally, all the nutrients would come from soil that we "grew" via compost.

The catch is that we're using closed containers that are watered from below and use peat/coir as their growing medium--in order to wick moisture properly--and as a result need outside nutrients. The loop is not closed. Because we don't want to spend a lot of money to reinforce our roof structures, we can't use heavy composted soil; light weight medium like peat and coir are our only options.

So.

We use organic--with a few exceptions--which limits our choices, has lower nutrient levels, and is more expensive. Unless there's a sale.

A local gardening center was changing their product line and in the process getting rid of all their Espoma products at 50% off. I bought plenty. If you're in Chicago, you might want to see if they've any left.

With all these different nutrients, I have a chance to make my own blend. Let me back up a bit and say that in the past we've used some Miracle-Gro Organic 7-1-2. Plenty of negatives: Big company that makes most of it's money polluting; Not balanced- too much N, not enough P and K. I think it showed in our results. Add to that our local supplier of Bradfield Organics stopped selling large bags. So I thought, this year I'm going to try mixing my own. How hard could it be? A few clicks with google and it'd be sorted out.

Not true. And so the reason for this post, which is basically a copy of an email I sent to H2, my co-blogger.

To begin, I decided what blend I wanted to end up with, and how much I needed.

For my 2 Mammoth Melting Pea SIPs, I wanted 6 cups of slow release 5-10-10. (Peas/beans fix nitrogen, so the N should be lower. And don't forget the pea inoculant.)

My base, and all the nitrogen (N), came from Espoma 5-3-3. This means 5% (by weight) of N, 3% P, and 3% K are available to the plant. I also have a bag of Phosphorus (P) from Espoma 0-46-0, as well as Potassium (K) from Espoma 0-0-22

The 5-3-3 Plant-tone (pdf) has all the trace elements.

Now the math. This link is the first place that I have seen a detailed explanation. Fortunately it's not that complicated. It does make it clear to me that all the people I've talked to/read about how to combine fertilizers really had no idea how to do it and were blowing smoke. Home gardeners just don't do this kind of thing.


A recipe to make 1 pound, roughly 3.5 cups, of 5-10-10.

Meaning 1 pound of fertilizer with .05 lb of N available, .10 lb of P, and .10 lb of K. The basic math can be used to create any mix you'd like.

All the fertilizer numbers are by weight, not volume.

The trick is to remember that 1 lb of delivered NPK rated 5-10-10--available to be used by the plants--will weigh more than 1 pound. We're after the weight of the NPK, not the total weight.

• Start with the most complete component, one with a little of all three.

By definition 1 lb of 5-3-3 has .05 lb of N available.

• The 1 pound of 5-3-3 also has .03 lb of P available. I subtract this from the .10 lb that I require, leaving a deficit of .07 lb. A pound of 0-46-0 has .46 of a pound of P available. I don't need that much, only .07 lb. The total amount of 0-46-0 to add to the mix is .07 divided by .46 or 0.15 lb.

• The 5-3-3 has .03 lb of K available. I subtract this from the .10 lb required, leaving a similar deficit of .07 lb. A pound of 0-0-22 has .22 of a pound of K available. I only need .07 lb. So the total 0-0-22 added to the mix is .07 divided by .22 or 0.32 lb.

Result: 1 lb of 5-3-3 plus 0.15 lb of 0-46-0 plus 0.32 lb of 0-0-22 gives me 1 pound of 5-10-10.

Like I said it's confusing. If you put the blend on a scale, you'll have 1.47 lbs of mix to each pound of the actual nutrients delivered. But that's how fertilizer is "measured".

Because SIPs/earthboxes are fertilized by volume not weight, I'll have to estimate how much to use. My SIPs need 3 cups per box. I'll be mixing my fertilizer by weight and applying it by the cupful.

[Newer post with an easier to use formula, here.]

Edited on 6.5.09

To use the above formula, I measured the density of the three components.

• 3 cups of Espoma 5-3-3 weighs 1 pound (454 grams)
• One cup of 0-46-0 weighs 320 grams
• One cup of 0-0-22 weighs 390 grams

To make approximately 3.5 cups of 5-10-10 fertilizer, I need:

.15 x 320=.20 or 1/5 th of a cup of 0-46-0
.32 x 390 = .375 or 3/8ths of a cup of 0-0-22
3 cups of 5-3-3