Pennypack Farm and Education Center

Topic: SOIL

Thursday, October 22
7:00 -8:00 p.m.

Healthy soil is needed to produce healthy vegetables. What is soil and what makes it healthy? How has the farm restored its soil's health and what can you do at home?

Registration and payment is required.
Fee: $10 / person

To register, send an email to education@pennypackfarm.org
or call 215-646-3943 x3
Provide names of attendees and contact info.

Last time I wrote about the equinox, which is a seasonal marker without much impact on the vegetable kingdom. But another seasonal marker is approaching, one that we really notice here at Pennypack Farm. The frost date is the first night of the year when frost forms in our region. Typically, that's October 10 around here.

The scientific definition of frost is a little confusing, but essentially, the plant surfaces are below freezing and are cooler than the surrounding air. Dew forms as ice instead of water on the surfaces of leaves. For many plants that we grow at the farm, frost is the end, or the beginning of the end.

Basil is the first to go. The leaves of basil will be blackened by temperatures that are significantly above freezing, as many of you have discovered in your refrigerator! Beans will be killed, and tomato plants, and peppers. We can spare these plants if we cover them with the white row cover, which will prevent the frost from forming underneath. However, given the feeble condition of the most vulnerable crops this season, we may not bother.

Some of our fall crops can sail through one or more frosts with little damage, including the mustard family (broccoli and turnips), as well as lettuce and root crops like carrots and beets. In fact, those crops will taste sweeter as a result of diminished water uptake and a higher proportion of sugar in the plant tissues.

Another victim of frost will be one of our most difficult weeds, galinsoga, a native of South America. It will save us a lot of weeding effort in the carrots when a frost hits. On the other hand, some weeds come on strong in the colder soil of fall, such as chickweed, which is also very frost hardy and is capable of burying our lettuce.

Right now our top priority is digging up our sweet potatoes, which can sustain damage when the soil temperature drops below 50 degrees. We dug up about half the crop yesterday, and it is a bumper crop, though there is some cosmetic damage to the tubers' surfaces as a result of the wet soils. After digging them up, we spread them out in the greenhouses, and close the doors to raise the temperatures to 85 degrees for about two weeks. This is called curing and helps to ensure storage life and sweetness. Look forward to an abundant fall!

Somehow I missed the fall equinox, but farmer Jessica informed me it happened yesterday at 7:05 am. Like most celestial events, the equinox is the province of astronomers (and in ancient times, of shamans and priests). But the chickens seem to know all about it. Their egg production has dropped sharply, to about half the pace of spring. In commercial egg operations, lights are used to fool chickens into laying. We haven't gotten around to that here; whether we should do so would make a good ethics debate at our farm lunchtime.

Some plants and insects seem to have a different clock, based on cumulative heat instead of light. This season has been about 20% below normal in cumulative heat (cooling degree days is one measurement often listed in the newspaper weather reports). I was astounded, but not altogether surprised, to see hundreds of fireflies rising off the grassy areas of the farm yesterday, a sight I never recall seeing this late in the year. On the other hand, I was saddened, but not altogether surprised, at the below average harvest of winter squash this week. Consequences of a strange season.

September around here is the month of the goldenrod, one of our most beautiful, fragrant, and useful wildflowers. Con McNutt, the retired FedEx driver who is one of our bee keepers, says the goldenrod is a critical nectar source to help the bees overwinter. This cold and wet year has been terrible for the hives. So I had mixed feelings as I mowed down a big patch of goldenrod today to prepare ground for our new vegetable field.

This new field is at the far east end of the farm, over towards Wittmer Road and the College Settlement Camp's facilities. We expect the soil to be similar to the soil we are cropping already, but the terrain is a little more sloped. That will be helpful with drainage, but problematic with erosion. In the next few months we will plow the whole area (about five acres), establish a cover crop, and erect deer fencing - all before the ground freezes hard. It's enough to make a farmer tired. One thing I always say when faced with endless tasks, like hand weeding, is that it's best to look backward at the work you've finished.

And at next Saturday's Harvest Fest, we can celebrate all that we've accomplished so far at Pennypack Farm.