"Lawns should be fertilized in early spring"

In the north (USDA Zones 2-5): wrong. Research by the University of Minnesota shows that northern lawns actually suffer somewhat from early spring fertilization. Jolting your grass awake too early—when soil is still cool—stresses grass plants and causes them to perform poorer when faced with the heat to come later on. In the north, you should NOT fertilize your lawn four times, as the major lawn fertilizer companies try to tell you. Two (late May and mid-October) is adequate, three (late May, mid-July, and mid-October) is plenty.

Wait until late May/early June. If you fertilized your lawn in the fall, your grass is just fine right now, and should be allowed to become more active by the increase in soil temperature and rising angle of the sun, before giving it another dose of drugs, organic or synthetic.

. "Dirt is dirt, and ‘fill’ is dirt"

Boy, can this myth bite you in the butt. I’m doing a job right now in west Minneapolis, and the homeowners raised their large, sloping yard by paying $400 for “fill” from some earnest guy they trusted. If I find one more rusted section of a swing set in it, or another log big enough sit on, while I’m digging the foundation for a stone wall, I’m going to crack.

I had the fill tested. The pH was 7.6 and it was about sixty-percent clay. It includes 3” to 6” stones, Class V gravel, and the aforementioned swing set. I’m planting trees and shrubs in it, and seeding some of it for lawn. I’ll deal with it, but my extra time, and expense to the homeowner, could have been avoided.

Never order what is advertised in the trade as “fill” for areas to be gardened or landscaped. Fill will almost always have utter crap in it, bits of asphalt, rocks, deer skeletons, you name it. You use fill for underbase, for when you need to raise up an area but will be adding at least two feet of good black dirt on top of the fill.

“Black dirt” also runs the gamut. Never order dirt for your yard without first seeing it. You can run into a lovely looking pile of black dirt at a supply yard that, upon closer inspection, will be little more than peat-coated balls of pure clay. Pulverized soil means it has been run through a machine and screened and will be the highest quality. Unpulverized is often quite good. For you local Renegades in the Twin Cities, you always get a good-quality black dirt product from Hedberg Landscape Supplies in Plymouth (763-545-4400), Gertens in Inver Grove Heights (651-450-0277), or, the best, Dale Green Company in Burnsville (952) 894-5812. Dale Green sells a variety of mixes, including a mineral soil, horse manure, and sand mix that is superb. All deliver.

For those of you outside the Twin Cities and around the country, call around, talk to landscapers in your area, visit landscape supply yards, and find out who has good “black dirt,” and who doesn’t. It matters.

"The best time to plant trees is in early fall"

Not true. Welcome to the fastidious and convoluted world of the Renegade Gardener.

Redbuds (Cercis canadensis) should be planted in spring, as early as possible. It’s a plant culture thing, don’t worry about it, all you have to know is that redbuds nearly always die if planted in the fall. Same with magnolias. Plant mags in the spring, not in the fall.

MOST trees prefer early fall planting. Oaks, maples, lindens, all your deciduous trees (except the two noted above), plus your evergreens such as spruce, firs, cedars, etc., do best when planted in the fall. The principle is that trees are big engines, and need good root development in the first growing season, in order to survive the blazing sun and charming 90 degree temperatures we call summer up here in the northland. Plant trees in April or May, and they have only 60 to 90 days to grow roots before the intense, withering heat of July. Plant a tree in late August or September, cover the planting area with 4-6” of shredded bark, and the tree will grow roots well into December. (Yes, it will. In this case, you are mulching to keep the soil warm). Then it goes dormant.

Then the tree fires up the root activity again in late April/early May, meaning that by the time the mid-summer heat hits, when the tree needs to suck up a lot of water to survive, the tree has had five-and-a-half months to establish a healthy root system (September, October, November, half of December, May, and June). July hits and it’s no problem.

Now the convoluted part. You should know a little something about how – and when – northern nurseries dig trees. Many varieties of trees are dug from the fields in early spring, for the start of the landscaping season, then dug again in late summer, to restock the shelves and because that’s when a lot of landscapers and homeowners correctly plant trees. But some trees can only be dug in the spring. Birch, for instance. You can’t dig birch in the summer or fall Birch just don’t like it. They die. Meaning that the birch you buy in September was dug in March or early April, and has been sitting in a container or BB all summer. It’s been watered, sure, but it has a relatively tiny root system. Not a good product to plant in fall. So you’re better off buying a birch in early spring, right after it has been dug, and planting it right away. Water the hell out of it all summer, and the plant will perform much better than if planted in fall.

Same with pines. In the north, pines are rarely dug in the fall. It’s a plant culture thing, don’t worry about it, just understand that a pine you buy in September was dug in the spring and has been sitting with its clipped little root system in a pot at some wholesale nursery all summer, before being shipped to the retailer for fall sale. You’re better off planting a pine in the spring, fertilizing it, mulching it heavily, and watering it every five days from the moment it’s planted until you let it dry down a little in October (to promote dormancy). If you must plant pines in fall, buy your pine from a reputable, full-time nursery, so you know that someone has been watering the thing heavily (and, if BB, has kept it heeled in since spring). Never buy a tree – or any plant – from a large box retailer that also sells lumber, tools, and toilets, I don’t care what time of year.

Final thought, any time you buy a tree, ask when it was dug. If the person doesn’t know and can’t get an answer, find a better nursery. For you comrades lucky enough to live in the Twin Cities, Gertens, Bachmans, Halla, Dundee, Otten Brothers, Linders, and Highland Nursery will always sell you a good, well cared for tree.

"A compost pile needs to be turned and watered regularly"

I can’t imagine gardening without access to the one to two yards of black, crumbly, sweet-smelling compost I have available to me in my compost bins on any given day. Yet when I ask gardeners if they compost, only about thirty percent say they do. (Funny, invariably they are the more successful gardeners).

Most gardeners who do not compost mention to me that they think it’s too much work, having read somewhere that to make compost you need to turn it with some regularity, and keep the pile moist when it dries out. It sounds like a bit of work to them—it is—and they think they don’t have the time.

Fair enough. So start composting today, using a variation of the “dry method.” In my version of the dry method, you build two side-by-side bins each at least 4’ by 4’ (6’ x 4’ is better). Every time you have any yard waste, such as young weeds, dried grass clippings, leaves, shredded Stella de Oro daylilies (it is important to run over dug-up clumps of these several times with the lawnmower, to be sure they die), just toss them in one bin. Don’t worry about “browns” and “greens” or any system of layering. Toss a handful of high nitrogen fertilizer (plain lawn fertilizer works well) on the pile as it gets half full, or don’t. Water it heavily when it gets half-full, and again a few months later, or just rely on rain.

Get one of the bins full, then wait a year. In the spring, after it’s warmed up, toss the stuff from the full bin (it will have settled down to half-full) into the empty bin, spraying it with water if it is very dry. Other than filling one bin periodically during the growing season, this means spending a grand total of about a half-hour per season on the process of making compost. In less than a month, the old stuff you tossed into the empty bin will be finished compost. This is how I’ve been making compost for the past ten years.

If your yard can generate more yard waste in a season than can be placed into one bin, build three bins side-by-side, fill two, then toss the stuff from full bin B into empty bin A, and from full bin C into (the now empty) bin B.

You can even do it with one big bin, 6’ by 6’ is a good size, 4’ x 6’ works, throw all your yard waste in it, and if you don’t add any nitrogen, never water it, never think about it, two years later you’ll find that underneath the very top layer of debris, you have finished compost. This is the true “dry method.”

You might think, “Wonderful, except it takes me two years to have compost!” to which The Renegade Gardener replies, yes, and if you don’t start doing it, in two years you will have how much compost?

"Wood mulch attracts carpenter ants"

This is an oft-quoted and widely circulated myth of urban legend proportions. Judging from my e-mails this season, it once again is gaining steam as it passes, mouth-to-mouth, around the country. It is false.

First off, know that a nice, thick layer of shredded bark or wood chips around your home is not a banquet spread out for the pleasure and convenience of carpenter ants. Carpenter ants don’t eat wood, a simple fact that surprises many (do carpenters eat wood?). Carpenter ants can bore through solid wood, however, and do so for the sole purpose of building a nest. They will nest in live and dead trees, and fresh or rotting logs and stumps. And since a telephone pole, fence or porch post, or the wood frame of your house, look and act a lot like dead trees to them, they will sometimes build their nests in these man-made structures.

But the wood mulch on your property, including the wood mulch around the home, doesn’t in any way attract or draw them in. Homes surrounded by lawn, dirt, cocoa bean or pecan husks, “decorative” rock (with or without black plastic), or faded Astroturf have just as good a chance of hosting carpenter ant nesting activity as any surrounded by wood mulch. Wood mulch is not food for them, nor is it in any way suitable nesting material. These are facts corroborated by the many university experts and professional exterminators with which I’ve conversed.

We have a lot of trees surrounding our homes in Minnesota. Also wood piles, stumps, and rotting logs. So we have carpenter ants, like the rest of the nation. The best thing you can do to keep carpenter ants from nesting in your home is keep the woodpile as far from the house as possible. Clear fallen trees and logs out from near the house, also. Have stumps ground out fully anytime you fell a tree.

If you see carpenter ants near or in the home, you need to find and eradicate the nest. Just remember that wood chips and/or shredded bark, if present, had nothing to do with the infestation. One expert with whom I spoke is conducting research to support his theory that black plastic under “decorative” rock is more of an attractant to carpenter ants, since the soil under the plastic stays dry, and is easier for ants to navigate. You can imagine my delight if that proves true.

The Virginia Tech Extension Service has a decent little primer on carpenter ants at http://www.ext.vt.edu/departments/entomology/factsheets/carpants.html

"Watering my trees and shrubs is covered, because I have a lawn irrigation system"

Boy, the number of times I’ve heard that one. I’ll keep it short: If you have a built-in lawn sprinkler system and you have just planted shrubs and trees in and around the lawn, you don’t have anything covered. A lawn sprinkler system typically means pop-up heads on a timer; they come up once a day or every other day and spray water in arcs around your lawn. This is not a good way to water shrubs and trees.

Lawn sprinkler systems get the foliage of the plants wet, four to seven times a week, for one thing. That encourages fungal disease. Second, trees and shrubs need a good, long, deep soaking every four to five days the first month after planting, and once a week after that, the first year, then every two weeks the following years—a far different schedule than that of lawns.

Trees and shrubs watered by a lawn irrigation system get too much water, too often, in the top two to four inches of soil, and next to nothing deeper than that. They suffer, struggle, and quite often die.

A lawn irrigation system is for lawns, period. Disconnect or redesign your lawn irrigation so that it skips your shrubs and trees. Then water the shrubs and trees by hand, or have installed a second system, using soaker hoses, on a different timer, and run that through the tree/shrub areas.