Temperature

Temperature sets the pace for everything else. Too cold and your plants just sit there, sulking, refusing to grow.  Too hot and they panic, drop their flowers, and focus entirely on survival instead of growing you dinner. Rude, honestly, considering all you did for them!!

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Planting out seeds:

• Soil temperature, not air temperature, decides when you plant seeds. A warm sunny day means nothing if the soil underneath is still cold. Seeds sitting in cold soil don't germinate.  They sit there rotting, waiting for conditions that never come. Get a cheap soil thermometer. It will save you more grief than any calendar date ever will.

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• Cool season crops, lettuce, spinach, peas, kale, actually like it chilly.  But DO NOT try to heat up the soil with a hair dryer.  (who... ME?)    Wait until the forsythia and dandelions are blooming, or until soil is about 10oC.​​

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Planting Out Seedlings:

• Tomatoes, peppers, and eggplant are started indoors, weeks before the soil out there is even close to ready, then moved out once conditions actually suit them. 

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• Know your last frost date for your zone, then work backward. Tomatoes generally get started indoors 6 to 8 weeks before that date. Peppers and eggplant are slower off the mark, give them 8 to 10 weeks.  Don't be like me, and  plant 12 to 14 weeks before the last frost, struggle to keep my plants healthy in a pot that is too small, watch as they get long and leggy and then struggle to  transplant them in the garden.    

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• Phenology has cues for transplanting out too, not just seeding. Tomatoes go out when lily of the valley is in full bloom. Peppers and eggplant wait for bearded iris or daylilies to start blooming, a bit later than tomatoes, since they're fussier about cold.  And old farmers will wait until after the full moon in May or June, (depending on your zone) as nights are often clear and cold during the full moon.

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• A warm afternoon is not the same as a warm season. One mild day does not mean the soil, or the nights, are ready. Harden off your seedlings first, a week or two.  Choose a shaded sheltered spot at first then gradually move them into stronger sunlight and wind.   Skip this step and watch weeks of indoor coddling undo itself in one afternoon.

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• Blossom drop is a heat problem, not a fertilizer problem. Once daytime temps climb into the mid thirties C,  plants abort their own flowers rather than waste energy on fruit they can't support. Feeding a heat stressed plant more nutrients doesn't fix this. It just wastes fertilizer on a plant that has already checked out for the day.

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• Nighttime temperature matters just as much as daytime. Plants need a cool down to recover. A string of hot nights stresses them as much as hot days, sometimes more, and unlike you, they can't just turn on a fan and complain about it.

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• Frost is not gentle, and it does not negotiate. One cold night can undo a whole season of babying.  However, if you are caught off guard, one way to help your plants recover is to water early, before the sun rises.  A gentle watering to wash the frost off the leaves before it penetrates can save tender plants.  If it's a hard frost and leaves are frozen solid they will not recover.  Cut the leaves and hope there are enough food reserves in the roots to re-establish growth.

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