Compost and caring for the soil

This coming Sunday, in addition to the warm weather plant sale, with weather permitting, we will be selling compost at EHCG:

Compost Sale

05/18/2014

11 AM to 1 PM

Eagle Heights Community Garden

$3 per half cart load

We are very excited to bring this important soil amendment to our gardeners. We sell this compost at-cost, ie we don't make any money off of it. This is sourced from the West Madison Agricultural Station, and composted of well-aged barn manure and food waste from campus. While that doesn't sound very appealing, I promise that this stuff is perfectly pleasant soil amendment gold. 

Speaking of soil amendments, let's have a brief discussion of what soil amendments are, and why we use them. Vegetables, fruits, and flowers require both macronutrients and micronutrients to grow. While carbohydrates, proteins, and fats are important macronutrients for people, plants require nitrogen, phosphorous, and potassium (N-P-K) for their health. Each year that a volume of soil is used to grow plants, a fraction of the N-P-K is used up, making that much less available for next year's plants.

It is important to restore these nutrients through soil amendments, including compost, fertilizer, and/or leaf mulch, to get the most out of your garden. If soil amendment is neglected, your yields will drop, and your plants may show symptoms of either nutrient deficiency or disease. 

The compost sold at EHCG, as well as the leaf mulch available free in the gardens all season long, are inherently organic and therefore suitable for our organic gardening spaces. These amendments are also lower in N-P-K than fertilizer, slower-releasing, and generally can be applied liberally without running into any issues. This contrasts with fertilizer, which can be bought either organic or synthetic, both of which are higher in macronutrients. (Organic fertilizer is generally lower in N-P-K that synthetic.) While these nutrients are important for plant health and growth, too much can result in fertilizer burn, a leaf "scorch" resulting from exposure of a young plant to too much nitrogen. If you apply a lot of strong fertilizer all at once, there is also the possibility that most of it will be washed away or lost instead of being taken up by your plants.

It is a good idea to invest in both a low N-P-K, slow release amendment (compost, leaf mulch) as well as a high N-P-K, quicker release fertilizer. I incorporate leaf mulch into my plot all season long, both for weed suppression when laid down thickly, and nutrient incorporation when I turn it into the soil in the Fall. (It has all season long to break down in my plot.) I also buy a half-cart of compost every Spring to surface-dress the soil. As I plant heavy feeders, such as tomatoes, eggplant, peppers, and squashes, I bury a small amount of organic fertilizer into the soil as I transplant, and periodically fertilize, in small quantities, throughout the season.

When applying fertilizer to tomatoes, keep in mind that nitrogen will spur the growth of green foliage, but not fruit. Tomato fruiting is actually encouraged by calcium, not nitrogen, so I hold off on fertilizing tomatoes once the plants start putting out flowers. I also bury eggshells into the soil as I transplant tomatoes to provide a slow-releasing calcium reservoir.

I hope to see you all at the transplant and compost sales this coming Sunday. Happy gardening.