It (Could Be) Cold

I see a lot of gardens under wraps this morning, plants covered with upturned buckets or flowerpots, or blanketed under . . . well . . . blankets. Day after day of balmy temperatures have made it hard to hold back finally getting vegetable and flower transplants out of their pots and into the ground.

But temperatures just below freezing were predicted for last night (May 13th) and everyone got a wakeup call: Freezing temperatures, which could kill tomato, marigold, and other tender plants, are still possible. It’s all about averages; around here, there’s about a 10 percent chance of a frost the middle of May.

The likelihood of cold, frosty, or freezing temperatures has been detailed -- see http://cdo.ncdc.noaa.gov/climatenormals/clim20supp1/states/NY.pdf -- for locations throughout the country. The closest weather station connected to that site around here is in Poughkeepsie, and in mid-May that site has a 50% chance of experiencing cold weather (36°F.) and a 10% chance of of experiencing frost (32°F.). Cold air, being heavier than warm air, sinks to low-lying spots on clear still nights, such as last night, so my garden in the Wallkill River valley is usually a few degrees colder than surrounding areas, such as Poughkeepsie. Fortunately, temperatures last night here dropped only to 31° F.

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Not that lower temperatures would have done my vegetables or flowers any harm. I took the advice I’ve been doling out to others for the past couple of (warm) weeks, and held off planting anything that could be harmed by frost. So tomatoes, peppers, melons, and the like are still in pots that I moved into the warmth of the greenhouse last night.

I’d like to plant out all these cold-tender seedlings but chilly temperatures are predicted for the next few night. Even chilly temperatures, let alone freezing temperatures, are not good for tender plants.

Still, anyone looking out over my garden this morning would have seen white blankets over some beds and overturned flowerpots over a few plants. Because my garden is in a cold spot, temperatures well below freezing were not out of the question for last night. Cold enough temperatures could damage cabbage and its

kin, lettuce, onions, and other cold-hardy transplants that have been growing out in the garden for the past couple of weeks. I had some row cover material readily on hand, so why not, methought, throw it over some of the beds anyway? Just in case.

Throwing covers over plants at 7 in the evening is a lot more pleasant than waking up at 3 am with the sinking feeling that temperatures have really plummeted and then, if they in fact did, running outdoors in the cold darkness to cover plants.

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Fruit trees, shrubs, and vines present another story. A freeze won’t kill the plants, but low enough temperatures could kill flowers or developing fruit, as it did on many fruit plants last year. One frigid night and you have to wait a whole year for the next crop. Unfortunately, not much could be done about this situation. Fruit plants here are too many or too big to cover. My tack is to keep fingers crossed.

Critical temperatures for fruit damage vary with the kind of fruit, the stage of flower or fruit development, the depth of cold, and the duration of cold. Probably other things, too, such as humidity and plant nutrition. 

An excellent table of “Critical Temperatures for Frost Damage on Fruit Trees” can be viewed at http://extension.usu.edu/files/publications/factsheet/pub__5191779.pdf. So, put simply, 25°F would spell death to 90% of my apples, which are in full bloom, and pears, which are post-bloom, and 28% would do in 10% of their fruits. Plums, also post-bloom, tolerate a bit more cold.

In addition to crossing fingers, my tack is also to grow a variety of fruits, and especially native fruits.

Pawpaw blossom, from below.

(Apples, pears, peaches, and most plums are not native.) It’s not a chauvinistic choice; it’s just that these natives -- American persimmon, pawpaw, blueberry, grape, and gooseberry, to name a few -- are better adapted to our conditions. And not just the weather here. Pests also.

This spring has been the most perfect spring in a long time, with plenty of clear, sunny days and gradually warming temperatures that kept blossoms from jumping the gun. Playing the averages, the critical cold periods should be pretty much be behind us. As with the stock market, though, “Past performance is no guarantee of future returns.”

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Update, May 17th: Warm days and nights that are not too chilly are predicted for the next few days, so I planted out tomatoes and peppers today. I’ll still keep an eye on temperatures because there’s still a 10% chance of temperatures dipping to 36° as late as May 28th according to records at the nearby Poughkeepsie weather monitoring station.

Compost and Cucurbits

You’d think, this time of year, that all I’d be doing is sowing seeds and transplanting small and large plants. I am. But I’m also turning compost piles, getting ready to use that “black gold” this autumn. Why now? So the stuff has time to mellow and to make space for new compost piles that will be built from now through autumn.

Here’s my compost routine: All summer and into autumn I fill empty compost bins with hay, wood shavings, horse manure, weeds, kitchen waste, and old garden plants along with some sprinklings of soil, limestone, soybean meal (if extra nitrogen is needed), and sufficient water to moisten the ingredients. When a bin is full, which means loaded up about 5 feet high, it gets covered with a sheet of EPDM rubber roofing material to keep excess moisture out and to seal in whatever moisture is within. A numbered label on each pile gets recorded to remind me when the pile was completed, what went in, and, with the help of a 2-foot-long thermometer, how much heat, if any, was generated.

Fast forward to today. I’m flipping over the contents of two compost bins, one completed last July and the other last August, into empty adjacent bins. Turning over the contents lets me see how the compost

has fared over the past 10 months; some piles might still be a bit raw, others are just about finished and ready for use. No matter, I don’t need any compost yet.

No rule that says compost piles have to be turned at all. I do it because I like to see what’s been going on and so I can make slight adjustments, as needed.  Sometimes a little more water is needed. Turning the pile also gives me the opportunity to break up any clumps of material and render the finished pile more uniform.

One of the piles I turned this spring had so much undecomposed hay in it that I sprinkled on some soybean meal as I turned it. Even that wasn’t one-hundred percent necessary; the high nitrogen soybean meal just speeds decomposition. Leave any organic materials (that is, something that is or was living) piled together long enough, with a bit of moisture, and it will definitely turn to compost. As my bumper sticker reads: “Compost happens.”

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One more reason for turning and organizing all of last year’s compost piles is to make space for growing melons and squashes. My vegetable garden is very intensively planted, with 3 foot wide beds packed tight with one or more vegetables growing together or in sequence, perhaps even trained skyward to get more out of the space. The long, sprawling vines of melons and squashes don’t fit into this scheme of things.

The compost bins -- 4 foot by four foot by 3 to 4 foot high cubes --  are perfect for these vines. Three or 4 plants poked into the rich compost through holes made in the rubber roofing can sprawl to their hearts’ content, spreading out to cover the tops of the bins and then, if they like, draping down to the ground, even creeping along the ground if that’s their whim. 

Melons and squashes thrive in rich soil, and my plants roots couldn’t find themselves in a richer soil than the pure compost within the bins. Plenty of water is needed to plump up the fruits; the compost clings to enough water so that watering is hardly necessary.

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The only melon that does not get planted on a compost bin is watermelon. But even watermelon doesn’t go in the garden. It goes onto a pile of wood chips or leaves I had dumped here last autumn and winter.

In contrast to the muskmelons, honeydews, and cantaloupes, all which bear a few fruits and then give up the ship, watermelon vines just keep bearing and bearing until stopped by frost or short days. I’ll

need to get into the compost bins before frost and short days; muskmelons, honeydews, and cantaloupes will be gone and out of the way but watermelon would not.

Also, watermelons don’t demand a rich soil. “Soil” that’s either partially decomposed leaves or wood chips is poor in nutrients, to say the least. So poor that when I plant in the leaf or wood chip pile, I scoop out a generous hole and fill it with compost to get the plant off to a good start. During the growing season, I’ll occasionally dose the watermelon plants with some soluble fertilizer.

All kinds of melons thrive in heat, in the air and in the ground. Freshly turned compost and old leaves or wood chips aren’t static. They are decomposing and, in doing so, generating some heat. All of which makes for good crops of good-tasting melons.

Deferred Gratification

If there’s one thing I don’t like about gardening, it’s all the deferred gratification, all  the looking to the future. That future might be 3 or 4 weeks hence, when I’m planning to start harvesting the radishes that I’ll be sowing today. Or 8 or 9 weeks hence, when I’ll start harvesting tomatoes from plants I’m nurturing today and that I sowed in early April for planting out towards the end of May.

And it doesn’t end. No sooner will a large portion of the seeds and transplants be snuggled into this season’s garden than I’ll be sowing seeds of cabbage and broccoli for eventual transplanting in midsummer for harvest in autumn. Planning for autumn now! Shudder the thought, but it’s got to be done. I don’t want to even think about autumn’s impending cold weather with this wonderfully warming spring weather.

Okay, let me take a deep breath and resolve this not-living-in-the-present of gardening. It’s not really that bad. I figure out what has to be done -- a written schedule updated as necessary from previous seasons’ notes is crucial for this -- and and then immerse myself in the all-present of doing it. And it’s not all for end results; there’s the joy and satisfaction of watching plants grow and come into fruition and respond to my ministrations.

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In some cases, the longer the period of deferred gratification, the greater the satisfaction.

I wrote back in February about the excitement of seeing white roots of some yellowhorn tree seeds that were sprouting in potting soil in a plastic bag in my refrigerator. I planted all those in pots. But also, in that plastic bag, were some hackberry seeds I had collected last autumn. They were doing nothing. Nothing obvious, that is.

Seeds of woody plants that ripen in autumn have a dormancy that lasts until they think winter is over. Winter for my hackberry and yellowhorn seeds takes place in my refrigerator, which is ideal because the

temperatures that spur seeds -- and plant growth, for that matter -- awake are between about 30 and 45°F. That’s why yellowhorn seeds awoke back in February. Outdoors, the requisite number of hours in that temperature range might not have accumulated until around now.

Hackberry seeds evidently need to experience more chilly hours before they’re convinced to wake up, which happened last week. I potted up the delicate little seedlings.

In 20 years or so, those six hackberry seedlings should be large enough to be clothed in a corky bark that, especially in winter, displays crisp, achromatic

shadows reminiscent of the lunar landscape. Perhaps by then the plants will be old enough to bear pea-sized, date-flavored fruits. Not that the fruits offer much more than a nibble; within each pea-sized fruit is an almost pea-sized seed, leaving just a thin covering of sweet flesh.

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Sometimes -- usually -- it’s best to let Mother Nature do the planting. On a recent drive to West Virginia, where the spring season is about a week ahead of here, the mountainsides were awash in redbud bloom.

Usually, I not a fan of redbud. It’s the color. Pinkish purple. Yuk, and too flamboyant. At least, to me, from isolated trees that blare out their color from front or back yards.

But isolated redbud trees as well as large swathes of them livened up the scene as they nestled in among forests of trees

unfolding soft-colored, pale green blossoms and young leaves.

On a shorter time scale, I see Ms. Nature has also done a nice planting of cilantro. In the couple of beds where cilantro stood last year (from self-sown seeds of the previous year), small plants are now ready for harvest. And I didn’t even have to think ahead to plant them.