I believe I have earned the title of “phenologist.” No, I haven’t been measuring skulls to assess character, which is the realm of phrenology. Phenology, which I have been practicing, is the study of climate as reflected in the natural cycles of plants and animals.
For the past 28 years, I have recorded the dates on which various plants have blossomed or ripened their fruits. My interest was horticultural: In spring, plants blossom after experiencing a certain accumulation of warm temperatures; fruit ripening reflects, to a lesser degree, further accumulation of warmth. The amount of warmth needed to bring on those flowers or ripen fruits varies with the kind of plant, sometimes even with the variety of plant.
Depending on late winter and spring weather, blossoming dates for various plants can vary quite a bit. Microclimate also plays a role, so I’ve tried to always note blossoming on the same plant from year to year. This year, forsythia bloomed about April 1st,, the earliest I’ve ever recorded. Contrast that with last year, when it bloomed about April 15th. Or 1984, when it bloomed on April 25th! Over the years, forsythia bloom dates averages around the middle of this month, so this year is definitely early.
In the garden, seeds and seedlings can’t be sowed or transplanted until the soil has warmed sufficiently, which likewise reflects that accumulation of warmth. Some seeds or seedlings require more warmth before they can grow (or survive) than do others. Knitting all these phenomena together, I plant, for example, lettuce seeds when forsythias blossom, broccoli transplants when apples blossom, and sweet corn when dogwoods blossom.
These sunny days and balmy temperatures are heavenly – except that they’re also coaxing earlier blossoms from my fruit trees also, blossoms that could get burned by subsequent frosty nights. The earlier these trees bloom, the more chance for those blossoms to get burnt on a subsequent frosty night. The historical average date of the last killing frost around here is about the middle of May. Even warming trends might accommodate a frosty night or two that can wipe out a whole season’s harvest of apples or peaches.
Still, it’s a glorious time of year.
I felt healthier merely reading of a recently reported study comparing the nutrition and safety of fruits and vegetables that were grown organically with those grown conventionally. (Lairon, Denis. Agronomy for Sustainable Development, Nutritional quality and safety of organic food, A review. 30(1):33-41, 2010)
As far as minerals, little difference generally showed up between the produce grown organically and conventionally. The organic produce did, however, average significantly more iron and magnesium.
Fruits and vegetables are more than just minerals. They also contain phytonutrients, such as resveratrol (that much lauded natural compound everyone is so glad is found in red wine), which may help stave off certain diseases, perhaps even aging. Organically grown fruits and vegetables were much higher in such compounds than were conventionally grown ones.
Safety of any fruit or vegetable can compromised in a number of ways. Nitrates are a form of nitrogen that can build up to undesirable levels in leafy vegetables. Excessive nitrate intake can lead to, among other maladies, cancers and blue-baby syndrome. Nitrate nitrogen is also a form of nitrogen fertilizer used in conventional agriculture, so it’s not surprising that conventionally-grown vegetables showed the higher levels of nitrate levels. Pesticides are, whenever possible, avoided in organic agriculture, and when used, might include such toxins as microbes specifically toxic to the problem pest – Bacillus thurengienses (Dipel) for cabbage worms, for example. So again, not surprisingly, pesticide residues were much less, or nonexistent, on organically grown produce.
Microbial toxins are yet another potential hazard to our food supply. Organic and conventionally-grown foods did not differ in their levels of contamination.
I’m going to especially appreciate the organic lettuce I’ll be picking from out in the greenhouse in a little while.
I just finished off the last of my dried tomatoes, and the canned tomatoes . . . well, they have their uses, but they’re nothing like a fresh tomatoes. I’m now on my way to fresh tomatoes, the very beginnings, as the seeds have just sprouted.
This year I’m growing a dozen varieties. In cherry tomatoes, the one to grow is Sun Gold; it’s neither open-pollinated nor an heirloom, but it is most delicious. For canning, there’s San Marzano and Blue Beech, although some of the fresh tomatoes I’m growing, such as Anna Russian and Amish Paste are also good canned. And rounding out the fresh-eating lineup are Belgian Giant, Carmello, Valencia, Soldacki, Stupice, Rose de Berne, and Nepal.