The 2010 garden catalogs now arriving have me thinking about how to get the most out of my garden investment, whether climate change should be taken into account, and so on. After years of experimenting with such questions, I felt some expert insight would help with the climate change question, in particular. Fortunately, I was able to reconnect with old friend and seasoned "farmdener:" Lee Reich. I've been keeping up with Lee's gardening books for years, including his latest - Landscaping with Fruit. No doubt, many of you have similar concerns and will enjoy his responses.Introduction.
By his own account, Lee Reich "is an avid farmdener (more than a garden, less than a farm) who turned from plant and soil research with the USDA and Cornell University to writing, lecturing, and consulting...He writes regularly for Associated Press and publications such as Fine Gardening and Horticulture. His garden has been featured in such publications as the New York Times and Martha Stewart Living, has won awards from National Gardening and Organic Gardening magazines, and has been included in "Open Days" tours of the Garden Conservancy."
Treehugger: What are some of the changes you've seen and possibly home gardeners are seeing which evidence climate change? Lee Reich: I've kept pretty good garden records for over two decades of bloom times for selected plants and best times for planting some vegetables and annual flowers. There has been a definite shift to earlier warmth in spring and warm lingering later in the fall. Also, winter temperatures, which I've also tracked, now don't plunge as low as in years past.
Two decades of recording bloom and planting times.
I read that some plants synchronize pollination with others, achieving a collective pollinating insect attraction. Is that significant and is climate change capable of messing that up? I don't think this is a problem since everything is still in synch. I haven't noticed any such changes in the garden.
If I plant something in my garden that formerly grew only in more southerly zones, am I taking a risk? It's somewhat of a risk but one that I'm taking more of. Gardeners are always pushing the envelope of what they grow so probably do this anyway. It's just that more recently, more plants are surviving that wouldn't have survived in years past. Climate changes are a general trend, which isn't to say that some winter lows couldn't dip to those of years past occasionally, so we gardeners are probably going to get surprised occasionally.
Chester thornless blackberry, example of a garden variety that now survives well north of its traditional zone.
That's interesting. So, does all this mean I can move back my spring garden planting dates, and by how much? Yes. I figure, staying on the safe side, about a week.
Can you fill us in on the science behind what is going on?
Bloom time of woody plants and, to a lesser extent, perennial bulbs reflects general warming trends of the air and, in turn, the soil. Each vegetable has minimum temperatures at which its seeds will germinate. So by keying soil temperature to bloom times of specific plants -- forsythia, lilac, etc. -- it's possible to know the best dates to sow each kind of seed.
Do serious gardeners then monitor average soil temperature? They should, if they want to get the most out of the garden, specifically the vegetable garden. I want to be able to pack as many vegetables as possible into my garden. Timing is very important.
Gaging soil temperature.
Two years ago my garden was so infested with Japanese Beetles that their droppings were noticeable on my deck? It was repulsive and I wondered if the lack of soil frost several years in a row led to the infestation. Am I right in this thinking and what other pest changes are observed?
Interesting. Japanese beetles are the only pest for which I've noticed significant changes over the years. I used to have almost none of them, 5 years ago I had some, and nowadays I have plenty. I am not an entomologist but my guess is that the generally increased infestations are due to warmer weather. Year to year variations in infestations are keyed to summer rains, among other non-temperature factors.
I worry that the growing local food movement in northern states could be set back severely by infestations of southern or new invasive foreign pests. Is that paranoid thinking? Yes, I think that's paranoid. After all, they do grow vegetables in the south. And, generally, vegetables are not especially hard to grow, especially when farms are diverse, which most local farms are or should be.
What resources would you recommend for our readers. Sources of help and further reading for example. My books, of course! Beyond that, I'll be glad to list a few of my favorites.
- The Winter Harvest Handbook: Year Round Vegetable Production Using Deep Organic Techniques and Unheated Greenhouses, by Eliot Coleman (2009).
- Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long, by Eliot Coleman, Barbara Damrosch, and Kathy Bray (1999).
- The Backyard Berry Book: A Hands-On Guide to Growing Berries, Brambles, and Vine Fruit in the Home Garden, by Stella Otto (1995).
- The Backyard Orchardist: A Complete Guide to Growing Fruit Trees in the Home Garden, by Stella Otto (1995).
- The Vegetable Gardener's Bible: Discover Ed's High-Yield W-O-R-D System for All North American Gardening Regions, by Edward C. Smith (2000).
- Landscaping With Fruit: Strawberry ground covers, blueberry hedges, grape arbors, and 39 other luscious fruits to make your yard an edible paradise, by Lee Reich (2009).
- Weedless Gardening, by Lee Reich ( 2001).
- Uncommon Fruits for Every Garden, by Lee Reich (2008).
- The Pruning Book: Completely Revised and Updated, by Lee Reich (2010).
- The Apple Grower: Guide for the Organic Orchardist ,by Michael Phillips (2005).
- Gardening: The Complete Guide to Growing America's Favorite Fruits & Vegetables, by National Gardening Association (1986).
- The Grape Grower: A Guide to Organic Viticulture, by Lon J. Rombough (2002).
- The Organic Gardener's Handbook of Natural Insect and Disease Control: A Complete Problem-Solving Guide to Keeping Your Garden and Yard Healthy Without Chemicals, by Barbara W. Ellis and Fern Marshall Bradley (1996).