Potting mix considerations

I have been doing a lot of thinking and reading about potting mix recently. For one thing, it is only four months till we start seedlings for 2016! (And only a month or so before we winter plant seed for perennials.) For another thing, I am thinking about using lots of wicking planters for greens in the upcoming year to improve their survival in our dry climate. Finally, a movable greenhouse has many benefits. I have been considering making our hoop house on the Littleton farm moveable. That way, we could start hardy spring greens, and then, once they were going and the weather was a bit more moderate, I could slide it away and start summer seedlings on the new site. Right now, spring plants languish in the increasing heat in the house, while delaying the summer tomatoes and peppers, and the tomatoes keep out the Fall kale and lettuce. However, a movable greenhouse is a big investment, and it might be better to just plant everything in containers, and then move and swap those. An unproven idea that we might try.

Anyway, there are lots of reasons for me to be considering potting mix strategies right now. For the past ten years or so, I have been using compost/ peat/ perlite type potting mixes. They are a logical extension to my organic gardening philosophy of feeding the soil, not the plant. However, I just now did some research and found a forum thread where a member was advocating a bark/ peat/ perlite mix, with the ratios being 5 1 1, very light and airy. They then add some commercial slow release inorganic fertilizer. The reasoning behind this is that a pot of fine grained potting mix contains a perched water table, where the natural attraction of the water to the soil particles is greater then gravitational pull. This zone becomes airless and is off limits to roots. So, some advocate separating the two functions of potting mix; structural support, and the provisions of nutrients.  Of course, this is just what conventional farmers do; they view the soil as an inert medium for holding plant roots, and then douse the soil with chemical fertilizer. However, since the pot is already an artificial growing area with different conditions then the soil, it makes sense that a different approach might be warranted. As an organic gardener, I would use organic slow release fertilizer, or a liquid fish/ kelp product if I switch over to a coarse grained medium.

I may do some experiments to compare the two approaches.

I also may include a small pot or bag of worm castings in larger, long term pots, which would provide fertilization without gumming up the whole pot.

Here is a link to the forum thread that got me interested in this: http://forums2.gardenweb.com/discussions/2842847/container-soils-water-movement-and-retention-xxii?n=329


Summer of 2015 in review

I ran out of time to do weekly postings, so here is a summary of our season on the Littleton farm site. Overall, it was a great year! All of our trees survived and are growing well. The tomatoes yielded so abundantly that we sold them at Church, after the members and the Carmelites had taken all they wanted. Our favourite tomato varieties were taxi, moonglow, green zebra, black krim, black cherry, Ananas Noire, Siberian, and Cosmonaut Volkov. We also donated some to Christ in the City and The Divine Mercy Supportive care. We also harvested lots of squash, zucchini, and turnips, but it turns out that the members don’t really like turnips, so we will be planting less of them next year. As usual, the Costata Romanesco zucchini did really well at the beginning of the year, and the powdery mildew resistant PM straight-neck summer squash from High Mowing Seeds got off to a slow start but is still going strong. Our Mammoth Sunflowers topped 8 feet, despite a few wind storms, and we harvested at least some seeds ahead of the chickadees. We got at least one ripe cantaloupe, about the size of a soft ball. Next year we will try again to be truly successful growing melons in Denver. And we harvested cucumbers, beets, tomatillos, peppers, eggplant, lettuce, and lots of arugula. We tried growing beans up our sunflowers, but this was a failure. In fact, all the beans we planted gave a lack luster performance.

Due to the work of harvesting, we did not have time for infrastructure projects or planting Fall crops. In any case, due to the extremely dry weather in Denver during the Fall, late crops are hard to start.

We have lots of plans for next year. We will be rebuilding our fence to be more animal proof by attaching fine mesh wire along the base and laid out along the ground. Our greenhouse will be mounted on skids sliding on rails, so that we can start winter crops outside while the summer ones are still growing, and then slide the house over them latter. To help lettuce weather the dry climate, we will build wicking beds and shade structures, and to help the workers survive the heat, we will build arbors and plant some grape and hardy kiwi vines. We will be planting more trees, raspberries, hazelnuts, and currents, among other perennials. We hope to have more flowers and insect attracting plants.  We want to experiment with some sunken hugelkulture beds to see if we can get by without watering some crops at all. Our compost system needs to be improved put on track this Fall. We hope to plant cover crops of winter wheat and rye on some of the beds, and deep mulch others.

In a few weeks we will have a planning meeting to get things on track for next year, redefine our mission statement and project list, and reorganize our vegetable share plan. I will post more information as we go.

The fourth week of March/ the first week of April

Due to bad weather, we did not get as much done these weeks as usual.
In Littleton, we got the vegetable garden tilled, to create a better seed bed than was left by the tractor, and we got the fencing around the vegetable garden mostly set up. We planted rhubarb, lemon balm, and peppermint in our herb garden

We planted several hundred beet mix seedlings started in Littleton in the tilled beds in Lakewood. We also mulched some paths and cleared vines, weeds, and sticks from some of the fence lines in Lakewood.

In Littleton, we planted our fruit trees ( 1 meteor cherry, 1 montmorency cherry, 1 honeycrisp apple, 1 Red McIntosh apple, 1 golden delicious apple, 1 sweet 16 apple, 1 summercrisp pear, 1 Lucious pear, 1 Reliance peach, and 2 Italian plums, mostly on semi-dwarf root stocks.) We also spread lots of leaves and pine needles in the vegetable garden as mulch, and planted sugar snap peas, both from seed and as transplants, and Sugar pod 2 snow peas from seed.

The third week of March

In Littleton this week we rented a trencher and installed a water line and frost proof hydrant. We were donated a bunch of plastic storage units for our tools and supplies. Somebody also donated a picnic table and benches.

We planted flats of Sugar Daddy snap peas, Purple top white globe turnip, Yellow Granex onion, and radishes in the Littleton greenhouse under row cover, using our standard potting mix. We planted some small news paper pots of Sugar snap peas. (The greenhouse is unheated: however, at this time of year the double coverage should keep things from freezing.) We planted about 250 sweet peppers (Marconi Red, Jimmy Nardello, Ampuis, California wonder red, California wonder orange, and a few others) and 100 eggplant (Early black and Black Beauty) in plastic six pack with our standard mix. The peppers and eggplant are now in a heated frame at my house.

We started to pin down landscape fabric in our work area, which will eventually be covered by mulch or gravel.

In Lakewood, we decided that the old compost/ mulch area was unsightly and not very functional. We started the process of tearing down the old bins and forking out the compost materials. (Things did not decompose very well; they seem to have dried out.) We will be building new bins in the shade of the greenhouse, screened from view by a grape and kiwi arbor. We forked over 300 square feet of the beds that we rototilled last year to remove the grass, and re-mulched the paths. We also started gathering and piling all the rocks and concrete chunks on site to build a raised rock flower bed.

The second week of March

 Two weeks ago, we finished building an Eliot Coleman style high tunnel/ greenhouse, with two automatic vent openers. The frame was built of 20′ rebar rods sheathed in PVC pipe, with the ends buried in the ground.
We got a lot done this week.
In Lakewood, we planted seed lettuce, lentils, and peas in the greenhouse under row cover. The lettuces were various heat tolerant types. By planting them in the greenhouse, we will be able to select for the most heat tolerant plants to save seed from. Before we planted, we hauled all the old mulch and compost out of the greenhouse, since it might be harbouring slugs, and spread it around the trees. We also repaired the bridge over the irrigation ditch.

In Littleton, we planted Early Flat Dutch and Copenhagen Market cabbage, Waltham 29 broccoli, and a beet mix in flats in the greenhouse, under row cover. We used our standard potting mix, a blend of peat, compost, and perlite amended with lime, bone meal, azomite, and organic fertilizer.

We also cut up bushes to make a truck access, spaded the other half of the greenhouse beds, rebuilt the greenhouse doorway, and dug a ramp so that we can roll wheel barrows into the greenhouse.

A farmer kindly brought his tractor and chisel plow in to break up the vegetable garden area. So we now have 10,000 square feet of broken ground. (About a quarter of the whole field.) Since the weather is dry and hot, all the grass should be dead in a day or so. We will have to get to work quickly to take advantage of the open ground before weeds do. Part of the garden will probably be mulched in preparation for planting, part will be sown with a cover crop before tomatoes and squash are planted at the end of May, and some beds will be worked into a fine seedbed without mulch for planting cool weather, small seeded crops like lettuce.

New Littleton Site! Helping to feed the Carmelites!

The Saint Isidore Society has been allowed to use a new site; an acre field located near Gallup Street and Littleton Boulevard in Littleton CO. We will be growing enough produce for the nearby Carmelite convent, as well as for the participating members. We hope to eventually plant fruit trees and bushes, as well as a large vegetable garden.

Our site in Lakewood will be moving into its second year this spring. We will be continuing  our operations there as well as developing our new site in Littleton.

We have already erected the frame of a greenhouse on the new site, which should be ready for use in a week or so. It will be very much like our Lakewood greenhouse featured in earlier posts here: an Eliot Coleman style hoop house with a plastic cover.

If you want to participate, contact us and we will send you the exact location of the site.

Rocket and TLUD cook stove experiments

The Saint Isidore Society has been building small cook or camp stoves out of salvaged cans.

IMG_4119 IMG_4118 IMG_4112

(Pictures of our TLUD stove No. 2)

So far we have built four stoves: rocket stove 1, which was almost exactly like this instructable; it used four soup cans and a #10 can, and vermiculite as insulation; rocket stove 2, which was like number one with a chimney twice the height; a small biochar TLUD stove out of a soup can and another, slightly larger can, which was rather like the one on this site; and a larger and more robust TLUD.

Before I get into the results of our stove experiments, I will give a brief description of the principles behind each kind of stove.

Rocket stoves utilize abrupt right angle bends, an internal insulated chimney, and certain critical proportions to create an extremely efficient, nearly smoke-less burn. They can keep a few small sticks burning for a long time, unlike an open fire.

TLUD biochar producing stoves heat biomass in an oxygen poor environment, producing wood gas, the volatile components of organic matter. This gas is then mixed with preheated air, which produces a clean, efficient flame. They can burn agricultural waste, pine needles, etc., unlike a rocket stove.

Our rocket stove 1 burned cleanly, though it did produce a little smoke, especially when starting off. It boiled two cups of water in a covered pot in ten minutes. (For comparison, an electric stove with a glass top boils water in about six minutes.) We also toasted some marshmallows.

Our rocket stove 2 burned faster then number 1, and also produced some smoke. It boiled two cups of water in five minutes. However, we used two cotton balls dipped in alcohol to start this, and there was probably still some alcohol burning when we put the pan on. This may have skewed results. The first stove’s cotton balls had burned out a long time before we put the pot on, so those results are reliable.

The TLUD stove burned a soup can full of pine needles for about ten minutes, completely charring them all. It produced a hot, clean flame, but we did not try to boil water. The alcohol cotton balls we used to start it burned for ten minutes before the needles started to char. (In a TLUD the starter sits on top of the fuel and the charring moves down through it.) The small amount of pine needle biochar produced was not worth doing anything with.

We built another biochar stove out of two cans, (TLUD 2) a good bit  larger then the first one, and loaded it with wood. It burned well for twenty minutes with no smoke, but then went out abruptly, producing a lot of smoke. When we put it out and dumped it, we found that it had only charred the wood about half way down the can, so it probably could have kept burning for a while. The gas flame was beautiful, and looked just like a propane burner.
We did some research and found a few things that might have put out the stove prematurely. The fuel was too tightly packed, and unevenly loaded; a taller chimney would have drawn in more air; it should have been shielded better from the wind. So we tried again, this time loading the fuel until it could just barely rattle when we shook the can (the last time we had really wedged the fuel in), we put another can on top as a chimney, and we stacked bricks around it to keep the wind off. This time we got twenty-six minutes of clean flame and no smoke. When the fire went out we were left with about a cup of biochar, which we will use for potting mix.

Next we will retry our experiment on rocket stove 2 without the alcohol effect, and outfit both rocket stoves with shields to direct more heat to the pots. We will be building a larger and more robust biochar stove fuelled with wood instead of pine needles. We will probably be experimenting with larger rocket stoves and with a haybox cooker used in conjunction with rocket or TLUD stoves.

Advent wreaths



The Saint Isidore Society recently held an Advent wreath fundraiser at Our Lady of Mount Carmel Catholic parish in Littleton. Families payed to gain access to the event, and were given all the materials to construct an Advent wreath, and assistance if necessary. The pine cones and greenery had been collected a week earlier on a member’s mountain property. Participants also received a prayer booklet for the days of Advent. The Saint Isidore Society volunteers served refreshments and helped with the setup and cleanup. Everybody had a great time, and we will probably repeat this next year.

Farm update for August

The farm has been producing tons of vegetables, especially eggplant, tomatoes, and zucchini.


Here is just part of one day’s harvest.

Some things have not done so well. Due to a loss of labels, we have not been able to harvest any green tomatoes, since we can’t tell which they are. Watermelon are still the size of base balls. Winter squash are growing well, but still way behind where they should be due to late planting. Peppers are only starting to produce now. I am glad we keep them in the greenhouse, where they will have another month or so of growing left.

Sheet mulching has vastly out preformed the tilled beds, though we have no one variable trials to prove it.

I saved landrace tomato seeds from the farm; basically, I just saved seed from any plant that had produced, without worrying about variety or potential crossing. Over the years, the mix of varieties will adapt themselves to the location, soil, and growing methods. They will preserve enough genetic diversity so that something does well in any given year, but I will not have to keep fifty varieties pure and separate. I hope to do a post on landraces soon.

We salvaged a metal shed for the farm and are in the process of rebuilding it.

Farm update for July

We got all of our spring planting done, but some things were put in very late. We will be using row cover to hold off early frosts, so hopefully we get a yield from everything.

Squash and zucchini are doing well, and we have already harvested a few. Our best variety is Costata Romanesca, which has constantly done well for me here.

Our tomatoes are looking pretty good. There is a small amount of fungal disease, but overall the plants look healthy, and are loaded with green tomatoes. We have harvested a few ripe ones so far. We never got around to staking or tying most of them, so some of the tomatoes will probably be lost to sitting on the ground. Then again, some sources claim that in a hot dry climate, letting tomatoes sprawl helps keep them from drying out and getting sun scald!

Our peppers and eggplant in the greenhouse are growing like crazy! They really like the tropical conditions in there.

Our beans, melons, and cucumbers were heavily damaged by bugs. Some melon plants survived, but we were already late planting them, since a first planting failed to germinate. So they don’t have that good of chances. We replanted cucumbers, and our third try, surrounded by cut-off yoghurt containers, is doing well. Either the cups kept off the pests (possibly pill bugs) or a natural balance had kicked in. (Due to a very wet spring, pill bugs and sow bugs have gone crazy, and did a ton of damage in my home garden. Due to the fact that we are not on the farm site at night, we can not actually assign blame to them there, but the damage looks similar and there are lots of pill bugs about. Pill bugs damaging plants is a much debated topic on gardening forums and websites.) We replanted beans. The bush beans are still struggling, partly because the mulch and compost we planted them in went hydrophobic. We sprayed soap to correct this. The pole beans are taking off.

All of our trees have survived so far, and are doing well, with the exception of a struggling nectarine. Fire blight hit surrounding mature trees heavily this year, probably due to the wet spring.

We had a beehive placed on the property, but it died. We will be trying again next year. Hopefully we will have our top bar hives done by then.

Despite the wet spring, watering has been a huge chore. We are experimenting with small scale PVC watering devices, donated drip hose, and Ollas; traditional terra-cotta watering devices. An Olla is basically just a unglazed pot buried in the soil. It wicks water out depending on the dampness of the surrounding ground, and the plant’s needs. We are also building some waffle beds, and using rocks as a lithic mulch. These are techniques used by native tribes in the desert southwest.

The heavy storms in the Denver metro have mostly bypassed us, with only a small amount of damage to the site. The lines of trees along the fences and creek have done a good job breaking the winds, sustaining a fair amount of damage in the process.

We are beginning planting for the fall. We are planting peas directly in the ground, and starting cabbage, broccoli, kale, and brussels sprouts at a member’s house.

Weeds have been a constant problem, especially bindweed. The bindweed was  not stopped by our sheet mulch, but it was slowed down considerably.

WIth the main planting done, we have been working on organizational projects. We have been setting up tool racks, sinks for washing up, and a work station. We hope to build a solar hot water heater and a reed bed for one of the sinks.

We are finally beginning to see a bit of produce coming in! There is not much yet, just a few cucumbers, zucchini, tomatoes, and some greens.