We get a lot of perennial gardening question e-mails, and the most common myth I see over and over again is that the needles of pines, spruce and other evergreens cause the soil to become so acidic that nothing will grow. It drives me absolutely bonkers that so many people believe this without one shred of evidence to prove the theory. The real issue, in my opinion, is one of dry shade conditions under large evergreens. Large parts of this continent have alkaline soils anyhow, and it would take a literal mountain of needles to change alkaline soil to such a degree that plants fail and die. I say, enjoy the needles as an attractive mulch, or rake them up and put them in the compost pile.

It's a constant quest to find a plant that will cope with dry shade without the gardener having to water it almost constantly. It's trial and error, like so much of gardening seems to be. I've developed my "list" of plants to recommend for such areas, but I even hesitate to use it any longer, not knowing what fate the poor plants are in store for. Will they be watered?

Realizing also that gardeners want colour and plenty of it, I now usually suggest gardening in containers in areas with extreme dry shade. Grow coleus, grow begonias, grow Hosta, Astilbe and ferns in pots. Ask for BIG pots for your birthday and every other gift occasion. Group them artistically, fill them with stuff and you will have colour in deep shade.

Tracy DiSabato-Aust's book The Well-tended Perennial Garden is really the ultimate reference on summer perennial pruning, and we recommend it highly. It's available from most large bookstores, or through Timber Press.

And here is a sampling of tricks our readers shared this month:

Steve — somewhere in Ontario
"I pruned back my Obedient Plant (Physostegia) in early June and again in mid-late June. This kept it more compact throughout the summer and it still bloomed in the fall, just a bit later than usual."

Sherri — Cambridge, Ontario
"I have severely cut back Tradescantia (Spiderwort) with excellent success. Once the flowering has finished, I cut it down to about two inches and in a few weeks there is a whole new plant with just as many blooms for us to enjoy through the fall !!"

Anne — Aurora, Ontario
"What perked my interest was a hedge of Sedum Autumn Joy. I experimented with making a hedge with my Autumn Joy plants. I pinched back the plants when they reached approximately 8 inches. My hedge looks fabulous. Other plants that need height control, I usually also cut back early."

Elaine — Robinsonville, New Brunswick
"I have done summer pruning on my Silver Mound Artemisia. I wasn't sure what would happen but decided to try. They had grown too large and were falling over, and didn't look like mounds any longer. I was surprised to see that they came back and looked great."

Kathy — Tecumseh, Ontario
"I have found the best method for keeping Summer Phlox neat, ever-blooming and mildew-free is summer pruning. I prune back one third in May and another one third in July. The older stems get cut right back after they flower and I have them rebloom in late fall. It is difficult to cut back a plant before it flowers, but in the long run it is effective."

Tracy — Metuchen, New Jersey
"I have, with great success, pruned my hardy geraniums back by 1/3 to 1/2 after the first flush of blooms in spring into early summer. They will give me a second and third flush of bloom all throughout the summer and into the fall. In addition, they return each spring bigger, fuller and not at all sprawling."

Larry wrote, "I know this is the usual advice, but have you ever seen any proof of the supposed rotting that happens? I've been mulching for years, often in shade and in a far damper climate than yours, where you'd think rot would be more likely, but have always spread my mulch out evenly, right up to the base of and even over the crowns of perennials and I have never had any trouble with rot — at least, not in any way that seemed to be related to the mulch. And when I look at how plants grow in leaf litter in the wild, they seem to just grow up through the litter; there's never an "empty circle" [left] around them."

"I've been wondering for years now where the advice about not letting mulch touch the base of plants comes from and whether anyone has seriously looked into the question or whether it is some sort of urban myth."

Horticulture on the prairies does not have a long history, compared to Europe or even places like New England and the Mid Atlantic regions. A harsh climate indeed, it didn't the take waves of new immigrants long to figure out that even the toughest of apples, plums or cherries from their homeland would just not grow where January temperatures typically dip down to -40 degrees.

Williams focuses on four gentlemen who came to the Province from afar, all of them active plant breeders in years from around 1930 until their deaths. Percy Wright, Cecil Patterson, Bert Porter and Les Kerr all made significant contributions, and not just to prairie horticulture. A goodly number of their trees, shrubs and perennials have made it around the world, and some are still grown in gardens everywhere to this day. Do you like Asiatic Lilies? Without the efforts of these men, the rainbow of colours seen in gardens today would not exist. I've found 'Royalty' Crabapples growing far from their Saskatchewan homeland, same with 'Sutherland' Caragana and most especially 'Sutherland Golden' elder.

Right after college, I took part of a summer off and had the pleasure of spending time with two of these men, a chance to meet some horticultural pioneers and just talk to them, ask them questions, be in their presence. They are both now deceased, and I just knew it was a "now or never" decision. I was right. And I thank Sara Williams for finding answers to the questions I never thought to ask, and for introducing me to two other horticultural pioneers I never had a chance to meet.

QUESTION: "What is the best time in my area to transplant hostas? Do you just separate them with a shovel or how do you split them up?" Jackie — Au Gres, Michigan

ANSWER: In terms of timing, it's best to divide Hosta clumps when the new growth first begins in the spring. But... having said that, you CAN do it now or later in summer, early or mid autumn. In summer it might be wise to cut the leaves all back by half to help prevent wilting in the heat. New leaves will develop in a few weeks.

For simple moving or transplanting of a clump, if you dig a large rootball you can get away with it at almost any point in the growing season. If the plant seriously wilts and fails to perk up again in a few days, cut the leaves back by half.

The technique for dividing is simple: use a spade to dig a circle around the plant, then basically pry or pop it out of the ground. Shake off some soil, or use a blast of water to wash some of it off. For a large clump, just be brave and slice the rootball in two, a task I find easiest to do by laying it on the ground sideways. Slice each half again, to give you four plants. Sure, you will damage some leaves along the way but no serious harm done. Then just replant each piece and cut back the leaves if the weather is hot. If you want more divisions, use a sharp kitchen knife and your hands to break it down into smaller pieces. Aim for a chunk of root the size of your fist or larger, with at least 2 or 3 fans of leaves emerging.

This month we will DRAW for three winners, and each will receive a signed copy of the Perennial Gardening Guide. Winners will be announced in the July newsletter, along with a sampling of your experiences.

Our best-selling book, the Perennial Gardening Guide (4th edition, March 2003) is a handy reference used by gardeners across North America — written by John Valleau, horticulturist for Heritage Perennials®. Available at your local Heritage Perennials® Dealer.