Building Compost Heater V2

We receive a large load of horse manure mixed with wood shavings about once every four weeks from a local stable and the material is hot when it arrives at the farm. We are using this material to build version 2 of our compost heater. We encountered some problems with version 1 (see 11/24/08 post) and decided to redesign our concept. In V1 the compost was heavy and put a lot of pressure on the poly and we felt it might break though the plastic. We tried putting in some battens between the hoops and the poly to alieviate the pressure but they were hard to get into place. Meanwhile, the partially-finished pile cooled and froze so we decided to start over at our small, 32x13 heated hoophouse.


The basic plan is to build a pile along the side of the hoophouse and run 300' of 3/4" garden hose through the hot core of the pile and circulate hot water into hoophouse. We are now building the pile and will work out the plumbing details later. We first add an 8" layer of hot compost followed by a 2" layer of fresh chicken litter, mix it in a bit and water it in.

Since our water source is about 200' away and most everything is frozen, it is difficult to get a hose to the project. We have quite a bit of snow now so we're using that for a moisture source. After two or three layers we add more hose on top of the pile in the center. We have placed some 1x2 furring strips between the hoops and the compost pile.

The second picture shows the first few layers of the pile, about 3 feet high, and the hoses running through the pile. We have since added a second hose run and will add one more hose. We'll cover the pile with dry compost or dry leaves and cover the whole thing with a tarp; If we can keep the outside of the pile dry and insulated we should be able to force heat either into the ground or into the hoophouse.




Bucky comes out to the farm (We live a few miles away.) nearly every day. No matter how cold the temperature is, he spends most of his day trotting alongside the tractor, searching for mice (he eats them!), or curled up on his bed in the hoophouse. He is very protective of the farm perimeter and alerts us to every intruder. Yesterday we heard some loud barking and we saw two deer racing across the field in a foot of snow with our dog following behind. When the deer were off the farm, he turned and trotted back to the farm wearing a somewhat smug expression.

Blizzard watch for this afternoon so we better get things in order!

Vegetable Tubs in the Heated Hoophouse

These two pictures were taken in our small (13x32) heated hoophouse. We had a very late start in planting for the winter because our first fall CSA (19 members) kept us busy in the field covering crops and preparing for the winter. But now we are seeding every day but are still two weeks behind where we want to be.

We are attending a winter market on Saturday mornings at Inglenook Pantry in downtown Geneva. It's a small market in its second year, has five vendors, and a group of loyal customers who come to shop every week. Best of all, it's inside the restaurant and Connie and Mark Weaver make breakfast for the vendors. What a treat!

For now we are growing a few greens in pots for the market and the first picture shows some pots of radishes that were planted in December. They are growing very slowly but they ARE getting bigger! If they reach maturity, we should get about three bunches from each pot. Each week we start the quantity we think we can sell at the Saturday market. In about three weeks, as the temperatures start creeping higher we will begin moving the most cold-hardy pots to an unheated hoophouse.

The next picture shows some nice greens but, unfortunately, the farmer-in-charge forgot to put the tag in so we are not sure what they are. They taste good, though! Admittedly, it's a pretty small operation at this point but we need to go for quality and consistency before we try to expand production.

In addition to growing market vegetables we are starting herb pots, vegetables to be transplanted into the unheated houses and a few container peppers and tomatoes to sell at the spring market.

Yesterday we added a layer of hot compost to the big pile on the north side of the house and hope to finish it today when the snow stops coming down. We buried a hose inside the pile and plan to get hot water into the house and create a "hot zone" for tomatoes and pepper plants. Pictures should be posted in a day or two.

Germination Chamber

We are starting to germinate seeds for the new year in our heated hoophouse. We are keeping the temperature overnight at a minimum of 50 degrees. Maximum temperature is maintained at 80 degrees during the day by cracking the door open when the temperature passes 80.

Seed Germination Chamber

This year we decided to try using some of our coolers rather than the large insulated box we used last year. The heat source is a string of 100 conventional Christmas tree lights which use about 240 watts of power. These lights were on sale just after Christmas for only $1.25 a string and one string can provide heat to two coolers.
We put a web tray in the bottom of the cooler to make sure that the lights would be above the bottom in case there happened to be any standing water in the cooler - wet lights could be hazardous to the operator! We bought an
inexpensive digital themomenter at Menards for about $7 and put the probe into the bottom of the cooler. We added lights a few at a time until we could maintain a nighttime temperature between 75 and 80 degrees. It took about 25 of the little lights to keep the cooler 25 to 30 degrees above the ambiant temperature inside the hoophouse. We open the coolers in the morning to check the status of the trays and tubs and remove those that have started to germinate. Everything gets just a bit of water on the top to make sure seeds are moist.

The results have been pretty good and some of the greens have begun to germinate in just 24 hours! By the end of the day we'll have three coolers going and one will be maintained a bit hotter for peppers and tomatoes -- we're beginning to plant some of these to grow large enough to fruit to sell at spring markets.

There are a couple of things to watch for. First, if you take a partially germinated tray out in the morning, it should finish germination but it should be watered twice a day to keep moist. If you leave it in the cooler, you run the risk of some really leggy plants. When we get leggy ones we have been sprinkling a bit of potting soil to reduce the length of the stem. It's also a good idea to do a quick check in the late afternoon to see if any trays or tubs need to be removed.

We have a pretty bad mouse probem so any partially germinated trays need to be covered or placed in an inaccessible place although the mice seem to be able to go just about anywhere! They seem to prefer spinach, sunflower, and cilantro seeds and also baby lettuce seedlings. We are testing various kinds of traps to see which ones work the best.

















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