Saturday, October 17, 2009

A Chill Is In The Air

We're getting our first taste of winter this weekend. I know that sounds funny to some of you who have had winter weather already, some for several weeks! There are those of you in Nebraska who had 17 inches of snow last week, folks in Wyoming who had even more than that and gardeners who survived the year's first nor'easter in New England just in the past few days. It's strange to see all the photos of the trees, in full leaf, laden with snow.

That's dangerous, actually. Dangerous for the trees, that is. The leaves capture the snow as it falls--and it was a wet, flaky snow, too--and often times the weight that accumulates is too much for the trees to bear and you get a lot of breakage. Here's hoping that if you're in New England, your trees come through unscathed!

Here in the south, I'm almost convinced that we're never going to see the sun again. I don't know how those of you in the Pacific northwest do it. Really, I don't. And I hate to complain about rain, given that just two years ago we were on our knees begging for any drop of water that would fall from the sky, but enough already! Save some for next summer!

And now it's turning cold... and not just cold, but damp and cold--the worst possible combination--and not very inspiring when you have as much to do in the garden this fall as I do! I'm sure I'm not alone.

Speaking of things to do in the fall, I thought I'd run through a short list of "to do's" that have been on my mind lately. I find that many times, fellow gardeners just aren't certain of what to do in the garden in autumn or, perhaps more importantly, when to do it.

Fall cleanup. This can be a daunting task. Summer's lush growth is now collapsing into withering heaps and you, the gardener, must decide what gets cut back, which plants are allowed to stay standing for winter interest, who needs extra mulch to help bring them through the winter (surely none of you are growing plants that are borderline in your zone! ha!) and which plants must be dug and stored. In addition, you have to decide what you're going to do with all of the vast piles of "vegetable matter" that you're removing from the garden as you do go through and cut back and clean up.

Composting. I'm not going to get into all of the "how-to" details of composting here--only a couple of quick suggestions on what should and should not be included. If you have any plants that had particularly bad disease problems this season, such as roses with blackspot, zinnias with particularly bad powdery mildew, etc., the debris from those plants should not be added to your compost pile. It's highly likely that your compost pile will not get hot enough to kill off the offenders and when you spread the compost back out in the garden, you're just re-distributing disease spores throughout the garden. Also, much of the material that you will be adding to your compost pile this time of year is dry and "woody"--even stems from your perennials (consider the bloom stalks from something like purple coneflower)--so you have to be careful about keeping the proper carbon:nitrogen ratio and be cautious of overdoing it with that dry, woody debris. Even dry leaves can get you into trouble in your compost pile! Too much carbon, not enough nitrogen = no decomposition. Well, maybe slow decomposition, at best!

Leaves. What to do with them?!? I make leaf mould with mine. How does this differ from compost? Well, first of all, it is only leaves. I don't put anything at all but leaves in the leaf mould pile. Secondly, it's almost all carbon because by the time the leaves fall from the trees, they're fairly dry and have little green left in them, so their nitrogen content is nil. What does this mean for you? It means they take a long time to decompose, but that's okay. I would suggest running the lawnmower over them to chop them up a little and that will help them break down faster. However, I move mine to the area where the pile is first and then run the lawnmower through them. If you do it while they're still on the lawn, they're impossible to pick up once they're finely chopped, so I find it easier to rake them and move them first and then do the chopping. Can you leave your leaves on the lawn? Yes, if you mow them up into fine pieces AND if you don't have so many leaves that even the fine, chopped up pieces leave a smothering "mulch" over the top of your lawn. If you have a lot of leaves, like I do, it's best to remove them--or at least most of them. I love my leaf mould pile. It takes at least one season for them to completely break down, and sometimes two, but it's worth the wait. Leaf mould is like black gold as far as I'm concerned.

Watering. If you live somewhere where your fall has been dry (does anywhere like that exist anymore?), be sure that your trees, shrubs, perennials and lawn are thoroughly watered before cold winter weather sets in. Going into winter dry is very hard on plants, especially evergreens, so be prepared to do some supplemental watering if you're not getting the needed rainfall as winter begins.

Fertilizing. Believe it or not, autumn is actually one of the most important times of the year that you can fertilize your garden--especially trees and shrubs. You need to wait, though, until things are completely dormant. Here in Tennessee, Zone 6b, I usually wait until late November and then when I do fertilize I make sure that I use something that has a low nitrogen number with higher phosphorous and potassium rates. High nitrogen could spur late season growth and then that tender new growth will get zapped in the next round of cold weather. That's not good for you or for your plants. Roots are still very active at this time, though, and an autumn application of fertilizer will be picked up by the roots and stored, waiting for the warm weather of spring to kick your plants into high gear and get next year's growth well underway.

Mulching. I'm fortunate to live in a zone where I don't really have to mulch too much for the sake of winter protection. I do it because it makes the garden look neat and tidy for the winter and because then the mulch is already in place when the perennials start growing in the spring and I don't have to mulch around them. In areas where you do have to mulch to protect plants for the winter, use dry straw or hay. Bark or wood mulches piled up over the crowns of your plants will rot them (except, perhaps for roses). When you are mulching with wood products (bark, shredded, etc.) be sure not to bury the crowns of your perennials. Many of them will not tolerate it and will rot out during the cold, wet winter weather because of it. You'd be better off not to mulch at all.

Pruning. I only have one thing to say about this--please don't! Autumn is NOT the time of year to prune! Cutting back perennials is fine. I'm talking about pruning of trees, shrubs, roses and other plants. I repeat, autumn is not the time. People get carried away. They're out in the yard cleaning up, getting everything neat and tidy for the winter and they figure they'll just do a little pruning while they're at it. Please don't do it! Pruning in the fall opens up wounds on the stems and trunks of plants that don't have time to heal properly before the onset of cold weather. This, then, allows interior tissue of the stems to freeze and you begin seeing considerable dieback in your trees and shrubs. Some trees and shrubs, such as crape myrtles, can die back several feet during the winter if they are fall pruned. Roses are the same way. Most of my rose friends (since I don't grow them) would tell you only to cut your roses back enough to tidy them up and leave as much the plant standing through the winter as possible. Hard pruning should not take place until late winter/early spring. The same can be said for almost all of your pruning.

Trees can be pruned beginning late February and into March (later in colder zones), prior to leafing out. The trick is to do your pruning when the trees are bare and you can really see what you're doing and where you're cutting, but to do it within a few weeks of when the sap is going to begin flowing and the trees and shrubs begin active growth so that the pruning wounds heal as quickly as possible. If you need to do hard "rejuvenation" pruning on things like boxwoods or an old yew hedge, late February (again, TN, Zone 6b) is the time to do it. If you live where it's colder, you'll have to wait, and warmer zones can do it a bit earlier. The key is to catch them right before they break into new growth so that if you are cutting back into dormant wood, the hidden buds along the stems have time to receive the signal that they need to come out of dormancy and get with it! Here, the boxwoods begin to flush in late March, so I like to prune about the last week of February. In other zones, you can adjust accordingly.

Before I end, a word on Crape Myrtles. Crape myrtles are probably the most mistreated trees and shrubs in the landscape. They have endured decades of horrific mistreatment by being beheaded every year to force them to sprout forth in a medusa-like manner with their snake-like branches whipping and waving in the wind, striking out at unsuspecting passersby. I don't know who the idiot was that started this practice, but I have two words for it. STOP! IT!

I have a theory that this practice was started based on one particular plant, the variety 'Natchez'. The 'Natchez' crape myrtle received huge amounts of press when it was released and became one of, if not THE, most popular crape myrtle in the parts of the country where it will grow. People planted it everywhere! What they didn't realize was that 'Natchez', where it's happy, wants to be a 25-foot tree. That's what it's supposed to do, folks! But people planted it right up next to their homes, around their pools, in their courtyards and driveway turn-arounds. Landscapers planted them in tight spaces in parking lots and other places where they should never have been used in the first place and suddenly, they were much larger than anyone "thought" they would get. This was a classic case of planting the wrong plant in the wrong place. order to solve the problem, the beheading started. People realized that if they cut their crape myrtles back hard each spring, they would shoot up huge amounts of new growth with enormous heads of flowers on them--so enormous that the thin branches often can't hold them upright--and this became an accepted practice, a practice that has now infiltrated and poisoned everything we know about growing crape myrtles.

By the way, not every crape myrtle will respond well to the "beheading" method. Many of them do not have the propensity to sprout forth and flourish when they are treated that way, so be warned. There are now hundreds of varieties of crape myrtles on the market ranging in size from 2-foot shrubs to 35-foot trees when they are full grown, and in every size category they come in a stunning array of colors. Do a little research. Find the appropriate size plant that will fit the space you need it to at maturity and choose a color you love. But please, please, stop the beheading!

Happy autumn!


Tim said...

Great post! I can certainly relate to your comments about the weather. In metro-Atlanta, it's been nothing short of bizarre for the past few weeks! The sun was peeking out for just moments at a time today, but I'm still holding out hope!

Great "to do" list for fall. I actually printed the post and am hanging it in the garage, since tomorrow starts my official autumn clean long as it doesn't snow in Atlanta!

Yvonne said...

Very interesting blog, Troy. Here we are having a dry autumn and yes, I must get out there and start watering before it gets really cold. My garden was a disaster in two summers following dry winters but quite good this year following a wet winter - so it does make a big difference. I agree totally about abuse of Crape Myrtles - stop it now and get the right plant instead! And thank you for visiting and faving my own humble blog. Most kind.

Piet said...

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