23 July 2009

Growing by degrees

The food cycle has finally reversed flow, there is more food coming into the house than we are able to eat... time to stock the pantry. Without a greenhouse, our stored food supplies need to last until the third week of July. It can be a struggle, and usually means relying on spring greens, grains, eggs and dairy for the better part of June and July after the last of the root crops and potatoes. And I always put away more than enough canned green beans to cover the gaps before those first glorious snow peas are ready in early July.

Although we planted each of these crops about three weeks earlier than last year, our first harvests are no more than a week to a few days earlier. I, of course, had my hopes up for a logical three-week-earlier harvest. But every season is unique. In doing some research, I happened across the phrase "Growing Degree Days". It is a unit used to measure or predict the first bloom or maturity of a crop, or the emergence of an insect or pest. Temperature is one of the most crucial elements in crop growth, and generally triggers most of the cycles of the insect world. And we have had an abnormally cool June and July. Especially July. Our nights have averaged at 10C (50F) instead of the normal 16-18C (60-65F). Only a few crops will continue to thrive with these nighttime lows, such as peas and Cole crops. Roots, onions and potatoes slowed down. And heat lovers: beans, tomatoes, peppers, squash and cucumbers just hung around, waiting.

Growing Degree Days can easily be calculated (go to the link above at Wikipedia), by keeping track of the maximum and minimum temperatures, which I have been doing for years, in my garden records. Each crop or insect has a cumulative requirement of heat, or Growing Degree Units to flower, reach maturity or hatch out. It will be interesting to use this unit in the future, to calculate and predict crop maturity or expected pest emergence, in an ever changing climate.

According to planting dates, we should have had our first new potatoes July 1st, instead of July 22nd, which shows that the cool weather set back the growing season by three weeks. Quite significant. But our first taste of potatoes, since the last wrinkled-ones in mid-June, was well worth the wait: Yukons, one large golden potato snuck out from each plant in a row. Boy they taste good. It's kind of a nice break, not eating potatoes in the gap between the last wrinkled, sprouting aliens, and the new, apple-crisp crop. Like cleaning the palette. After all, we do eat our share of potatoes over the winter. And come June we have an abundance of eggs so I can make all of the pasta I dreamed of making in the winter egg-drought.

Likewise, there is nothing like that first sun-warmed tomato... We savored, half each, on a bed of lettuce and snow peas, with a yogurt-dill-cilantro dressing.
Broccoli won't be far behind... I usually can't resist snapping off the first head and eating it right there in the garden.

The larger carrots can be selectively pulled from the row, making room and giving sunlight to the stragglers from replanting the gaps. I couldn't resist pulling a few early parsnips to go with the feast. The smell of freshly pulled parsnip roots and leaves reminds me of coconut. Didn't have any coconut milk in the house, but this is what the aroma inspired: carrots and parsnips sliced, steamed, cooked in butter, with chopped mint, peppermint and finely chopped dates. New favorite.

Our last carrot planting was later than usual, after the cutworms marched through, taking two May re-plantings with them, I was too discouraged to plant again, until after we put the cutworm fence around the fallowed, cutworm free plot. The first week of July started with a flood and ended with a drought, I planted the carrots between 1" rains, and then the weather turned hot and dry, forming a crust on the surface of the soil. Larger seeds would not be worried by this, but tender carrot seedlings can really struggle with obstructions. And the heat was to continue for a week, so I experimented with laying a fine layer of hay over the beds, aiming for 50% coverage, like shade-cloth, to bring the soil moisture back to the surface and soften the soil, allowing the seeds easy emergence.

It worked beautifully, the carrots poked up between the mulch, and it has worked to suppress some of the early weeds. As the crop emerges, I gently part the mulch and concentrate it between the rows to further suppress weeds.


Mr. H. said...

What an excellent idea to cover the carrot bed with a thin mulch. We sometimes have the same issues with the soil hardening and thanks to you we now have a solution. I will remember this and try it next spring in my newly seeded parsnip row.

Throwback at Trapper Creek said...

The Pacific is so much colder than the Atlantic, we rarely have a summer night over 50 degrees. Very low humidity also.

I ran across some info. about mineral imbalances in soil causing cutworms to proliferate. The info was in "Why Weeds Grow."

Freija and Beringian Fritillary said...

Mr. H, the idea came from a sub-Saharan Africa growing technique for getting seeds up in drought conditions. It did the trick, bringing the moisture to the surface without cutting the light too much.

Trapper Creek, I'd gladly take your extra hundred days of the growing season! Thanks for the info, we'll check it out.

Throwback at Trapper Creek said...

Looks like we will get some 60 degree nights, but it will be 100 during the day to get 60 at night.

I don't think our growing season is that much different than yours. Our last frost is usually May 15 or 20th and first is around September 30th. Good luck on your new adventure!

Amanda said...

Interesting. Our harvest has been 2 weeks earlier than last year thus far.