I ate my first asparagus May 17, one week later than usual. Does that mean everything will be a week behind? No. The cold weather crops like peas are right on schedule. The cold ground will probably delay planting corn, cucumbers and squash which may or may not make them later than last year. Last July was the coldest on record in southern Maine. If this July and August are hot, the plants may well catch up to their usual time.

I am more interested now in what to expect for the last frost. We have not had as many frosts as usual for this time of year. While it is not getting as warm during the day as usual it is also not getting as cold at night. The frost-free date is most important for tender crops, especially the transplants like tomatoes, peppers, eggplant. You wouldn't want to have a frost after beans have come up either but usually crops that we plant by direct seeding will not be up before danger of frost has passed because their germination depends on soil temperature. I have to say that asparagus shoots are very tender to cold air and frequently are nipped even though the soil temperature told them it was all right to come up.

Frost is not influenced very much by soil temperature, however. It is caused by those arctic blasts of air the weather people like to talk about. A warm soil cools fairly fast so even a soil that has reached the temperature of 70 degrees during the day could cool enough overnight to allow cold air to freeze tender plants.

The latest I have ever had a frost is June 6th. I figure my frost free dates to be from June 1st to September 20th. I'll probably stick to those dates but I'll keep a weather eye just in case I have to throw blankets over some of my babies.

Among the plants that I won't have to worry about are onions. I have planted three rows of sets and two rows of seeds. I planted them later than usual just because the garden wasn't a comfortable place for me to be. Who wants to be playing in cold soil while being bundled up against a cold wind? It kind of takes away some of the pleasure.

Someone told me of onions rotting in the ground because it was too cold. Not true. You could plant onion sets in the fall just before the soil froze and they would get going at just the right time the next year. In fact, that is the absolute best way to plant another member of the family, garlic.

I didn't doubt that the onion sets rotted. I just didn't think it was due to cold. "It must have been a clay soil," I said. Yes, it was. How did I know?

Elementary my dear Watson. Onion sets will not rot because of cold ergo it must have been something else that caused the problem. What else could have killed the life in those miniature onions whose life had been started from seed last year and stored by drying them? A disease, bacteria or fungus of some sort may be possible though onions are really very hardy and resistant to attack. The most likely cause of death, I reasoned, was drowning. The particles in a clay soil are so close together they do not let water drain or percolate through it. Clay soil is the last to dry out. Onion sets planted in a clay soil that then receives an inch of rain are likely to be in trouble. I'm assuming that no one would plant sets in soupy clay but that could be an incorrect assumption, I suppose.

If you have a clay soil, put the organic matter to it. Make a lot of compost and work it into the soil. Use a lot of bulky materials that are not high in nutrients like horse manure with wood shavings, hay mulch, leaves and the like. The organic matter breaks down into a magical ingredient called humus that is important in all soils but essential in clay.

İMay 18, 1997

Mort is a husband and father. He authored a book, Gardening For Independence and was named Environmentalist of the Year by Down East Magazine in 1987. He is a consultant for organizations. You can eat his organic produce at his son's southern Maine restaurant. His address is 802 Bald Hill Road, Wells, ME 04090.

Mort retains all rights to his columns. Anyone interested in using them can get the rights at a very reasonable rate.