The U.S. Department of Agriculture has upgraded our hardiness zone for most of the Treasure Valley zone from 6 to 7a. The western part of the Valley is now 7b. Go to www.planthardiness.ars.usda.gov and enter your zip code in the upper left box for your exact designation.
Zone 7a means the average lowest winter temperature over several years has been 0 to 5 degrees F; Zone 7b means an average low winter temperature of 5 to 10 degrees F. These are general guidelines, and I wouldn’t burn the long johns yet. Remember these are averages, and winter lows may be warmer or colder than these temperatures.
Moreover, these zones don’t take into account microclimes, protected places in each yard. Some folks may find a spot in their yard where they can grow bananas, while the rest of their yard freezes. This official change has been made so late that nurseries may not be stocking zone 7-tagged plants yet. You’re better protected against plant loss if you buy perennials or woody plants that will tolerate zone 6 or even zone 5 winters.
In tacit acknowledgement of the home foreclosures around the country, there’s a new emphasis on growing trees, shrubs, ornamentals and even vegetables in containers. These are primarily aimed at renters and apartment or condo dwellers with balconies or tiny yards. When you move, you can easily move your containerized garden with you.
The popularity of hanging tomato plants may have preceded this trend, but I overlooked its purpose, if that was the intent. I made the connection with foreclosures and uprooted people when I noticed that Renee’s Garden Seed press packet featured seeds for many vegetable plants in containers, even including zucchini. This is a plant that can “walk,” taking up a lot of room in the garden before the season is over, so a container version is remarkable.
One Green World fruit tree nursery carries many varieties of trees grafted onto dwarf rootstock. That means the tree shouldn’t grow to more than about 10 feet in height at maturity. Dwarf and semi-dwarf fruit trees bear normal fruit in just a few years, much more quickly than standard-sized trees bear fruit.
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The usual guideline for growing vegetables is in “full sun” (that is, 6 hours of full sun). There are some vegetables that will thrive in less than six hours of sun: leafy vegetables such as lettuce, spinach, mustard greens, Swiss chard, arugula, endive, cress, broccoli and peas. Some of the leafy greens tolerate as little as three hours of full sun. Black-seeded Rocoto or Manzano chiles appreciate a bit of afternoon shade.
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Are we growing all vegetables right for proper harvest and cooking? I’m revising my thinking on two crops: Tuscan kale and cardoon. I’ve always grown Tuscan (also called black or dinosaur kale) kale to full size, then pulled off the better-looking leaves for harvest. Many of the leaves don’t look very appetizing by that time, having fallen prey to slugs, grasshoppers, and other leaf chewers.
A better way of growing this crop appears to be growing it more like lettuce. That is, harvest it young, and replace those plants with younger Tuscan kale plants.
In Ireland as in this country, folks growing cardoon have waited until September to tie up and blanch cardoon leaves so they can be cut off, strings removed, and blanched for table use. This is a large plant with spiny leaves, so it is daunting to consider tying it up. Most of us who grow it settle for growing it as an ornamental accent to our gardens.
My friend Kathryn Marsh, who lives near Dublin, said an Israeli gentleman laughed at her account of not using cardoon, and said in his country, folks use it young, with younger seedlings ready to replace those that have been harvested.
By last September, my cardoon had leaves that arched 4 feet, obstructing a path next to its bed. It would have taken more than two of us to have tackled that for blanching, so we didn’t even try. This year I’ll try harvesting young leaves.
Margaret Lauterbach: melauter@earthlink.net or write to Gardening, The Idaho Statesman, P.O. Box 40, Boise, ID 83707
