There was only one word for summer in most of the country this year and that was miserable. In our area we had 32 straight days of 100-degree-plus weather. Our nights were about 10 degrees warmer than usual and that meant the 100-degree mark was hit earlier in the day than in summers past. I heard similar stories from customers all across the country. Finally, the heat has broken and we are in the mid to upper 90's with true fall weather just around the corner.
I don't know about anyone else, but I don't garden in the heat. About the only thing I do is run around in the evening and make sure the water is going off and all the timers are working. Needless to say, after a month and a half of not being in the garden, I am chomping at the nippers. It must be how folks back east feel after their long winter months finally come to an end.
Fortunately, now is a great time for planting as well as pruning. And, while the mantra may be "fall is for planting;" it really should be "cooler days are for planting." Fall doesn't start until the Autumnal Equinox on September 22 and this is too late for most of the eastern half of the country. Plants should go in as soon as the weather turns. You know when that is. It is when you start to breathe again. You can feel the change in the mornings and in the evenings as the days start to get shorter. And, it is those short days that you want to stay ahead of. The more daylight, the faster the plant grows and vice versa. As winter approaches with its "blink of an eye" days, plants become dormant. This is known as photoperiodism--the response of plants to the daily duration of light. In actuality the plants are responding to the length of the night rather than the length of the day.
As humans who feel heat and cold we often see these plant reactions and associate them with temperature. For instance, like other flowering plants, Mums start to bloom as the day length shortens and, coincidentally, as the weather starts to cool. This year, however, our Mums are blooming in the heat, but they are still blooming because the nights are longer.
Why is this important for fall planting? Because when a plant starts to flower, it pretty much stops root development as it switches gears toward reproduction, and once a plant has completed reproduction (or flowering), it heads for a nice long dormant period where it will stay until spring provides shorter nights once again. By planting early in the "fall" season, we take better advantage of photoperiodism and the rhythms of the plant, giving the newly planted starts more time to grow before the long nights of winter tell them to flower and shut down.
Understanding photoperiodism can also help you to grow better plants indoors. At this time of year a lot of folks are thinking about potting up a few herbs for the long winter. Growing herbs in the house requires some special considerations, the most important of which is light.
There are several options for lighting indoors, but to keep herbs growing the best source comes from a metal halide bulb. The light from these lamps encourages leafy growth instead of flowering. If you have no ambient lighting or lots of overcast days in the winter, then a metal halide bulb is a great investment.
If you want to grow tomatoes in the winter or have flowering plants inside, then a high-pressure sodium lamp is the way to go. The spectrum of light in these bulbs mimics fall when plants are pushed to flower and set fruit. Some growers recommend a combination of the two lamps, but we use just the metal halides in our greenhouses and the growth over winter is amazing. There are some drawbacks though: we have to wear sunglasses if we go into the area while the lights are on, and we have heard reports that the mothership has landed.
Visit our indoor lighting section for more lighting options. No sunglasses, though...
TIL' NEXT TIME,
A FEW GOOD RULES FOR FALL PLANTING
1. All planting should be finished about 4 to 6 weeks prior to frost. This gives the plant plenty of time to establish roots and keep it from dying during the winter. By planting early, plants still have enough daylight to make one more little flush of growth.
2. Choose plants that are right for your zone. Choosing a zone 7 plant for a zone 4 climate spells disaster, unless you want to try growing indoors.
3. Mulch well. A three-inch-deep layer of small-particle mulch, like ground bark, should cover the ground around the plant but should not come up to the plant's stem. Leave a two-inch air space around the little plant. Don't worry about the mulch standing taller than the plant. In about two months the mulch will be ground level.
4. Water anyway; don't wait for the rain. Water well when the plant goes into the ground and continue to water whenever the soil is in danger of becoming too dry. If gauging this is hard, try one of our handy water meters. Inserted near the plant's root zone, they make it a snap to see if the plant needs a drink.