Friday, October 9, 2009

Cold doesn't end garden chores

I overheard someone in the barber shop say how quickly cold weather arrived this year. If you’ve lived in Colorado for very long, you know that the unexpected is the rule. The arrival of snow in the third or fourth week of September is not unheard of. I saw the first snow-rain here on October 8 this year.

The usefulness of covering plants will come to an end this week as night temperatures dip into the low twenties F and hard freezes prevail in most areas. Covers help with a few degrees under freezing but not with temperatures this low and repeated over several nights. Some of the hardiest vegetables such as kale, cabbage, peas and parsnips may survive. (Red Russian kale shown with frost on leaves above left, and two days later unharmed above right).

If you have automatic drip or spray irrigation for your garden, it’s time to be concerned about freezing of exposed backflow prevention devices. Until you are ready to get the water blown out of the device for winter, some precautions may be in order depending on how exposed the backflow device is (photo left). Wrap an old rug for insulation, pull a plastic yard bag over the wrapped device for waterproofing, and cinch with duct tape to prevent wind from ripping it off (photo right). This will generally get you by for a short period.

Do plan to remove killed tomato, squash and other warm season vegetable skeletons after a hard freeze. You can avoid overwintering many vegetable diseases and insects by doing a thorough fall cleanup.

Early blight fungus overwinters on diseased plants and some weeds. Remove diseased tomato plant debris and clear weeds from the garden. If the disease was severe, consider moving tomatoes to a new location next year if you have this option. The unusual bacterial spot seen this year also survives on plant debris.

Viruses that affect tomatoes such as Tomato spotted wilt and Impatiens necrotic spot cause yellow rings or spots on fruit. If you see these, remove plant debris because viruses survive in plants, not soil. Note that lettuce, pepper and weeds such as bindweed and nightshade will harbor viruses.

Thrips insects that spread viruses from plant to plant overwinter as pupae in soil crevices or on plant debris. Flea beetles that chew shotholes in leaves spend the winter as adults hiding under leaves, dirt clods and other protected sites.

Fall plant cleanup and fall tillage tend to disrupt all of these pests.

Photo cedit: Two kale (frozen and two days later) and two backflow preventer (open and wrapped) photos, Carl Wilson

1 comment:

  1. Re: irrigation protection, I did just that until a company could come out and clear the lines. The representative added that I should have also shut off the water supply valve that's in the house and drain the line (there's a drain valve adjacent to the shutoff) between the shutoff and the backflow preventer. Hope this helps.