Garden Detective

I love free stuff. And when you combine free with plants, I practically foam at the mouth. So when a press release from MillionTreesNYC hit my mailbox earlier this week, my antenna went up.

There are some catches, though. Despite the group's name, there won't actually be a million trees available for "adoption." The group is giving away 1,200 trees on May 10, 17 and 18 at four Council on the Environment of NYC Greenmarkets and at the Riverdale (Bronx) YM-YWHA's Environmental Fair, with 250 trees available at each location. Also, there's a limit of one per household. You won't get to landscape your entire property, but, hey, it's a tree. And free is a beautiful thing. (The group's name actually comes from its goal to plant and care for 1 million new trees across the city’s five boroughs by 2017.)

Limited quantities of the following species of trees will be available on a first-come, first-served basis: Red Bud, Dogwood, Cherry, Crabapple, Service Berry, Linden, Sweetgum, Oak, Tulip Poplar and Buckeye.

If you happen to grab one, you'll be required to register your new tree at www.milliontreesnyc.org. I'm not quite sure why, though I wonder whether the agency will send case workers to monitor the type of home you're providing. (Is there a such thing as Arbor Foster Care for those that are neglected? If so, I personally know of dozens of abused trees in need of rescuing.)

NYRP horticulture specialists will help get you started, with instruction on how to plant properly and then send you on your merry way. If you don't have a yard, as is likely the case for the many apartment dwellers who attend these events, there will be opportunites to get your hands dirty, anyway. Info will be available on volunteer opportunities, educational programs and, of course, contributing to MillionTreesNYC.

Here are the details:

• Saturday, May 10
8 a.m. to 2 p.m.
Borough Hall CENYC Greenmarket – Staten Island, St. Mark’s and Hyatt

• Saturday, May 10
8 a.m. to 2 p.m.
Grand Army Plaza CENYC Greenmarket – Brooklyn Prospect Park NW Entrance

• Sunday, May 17
8 a.m. to 2 p.m.
Inwood CENYC Greenmarket – Upper Manhattan Isham St., Seaman & Cooper

• Saturday, May 17
8 a.m. to 2 p.m.
Sunnyside CENYC Greenmarket – Queens, Skillman between 42nd and 43rd streets

• Sunday, May 18
8 a.m. to 2 p.m.
Riverdale YM-YWHA Environmental Fair – Bronx, 5625 Arlington Ave., at 256th Street

Heuchera (Coral bells), left, and Helleborus add color to shady spots.

Kathy, a reader from Little Neck, wrote, asking for plant suggestions for her shady plot. And she mentioned that hostas "don't grow well" for her.

Well, Kathy, hostas are pretty well represented in shade gardens across the New York-metropolitan area. Since you didn't say what sort of difficulty you were experiencing with them, I'll just quickly go over a few common problems.

If you're noticing round holes in the leaves, slugs are likely the culprits. If you kiss your plants goodnight in the evening and wake up to find them missing from the garden, then you can blame deer or rabbits, though I don't think that's a likely problem in Little Neck. If you're noticing mottled foliage, yellow rings or dots on the leaves, that would indicate a virus, in which case it's best to dig them up and throw them out.

Other problems can be caused by chemicals, frost damage or insufficient shade.

No matter. Since you've decided to move on, I can tell you about some beautiful and hardy shade plants that thrive here, but first I want to tell you about one plant that will not grow well - grass. If your garden is very shady, don't even bother trying to plant a lawn. Sure, nurseries sell seed mixes labeled for shade. But I don't care what the bag says: They won't produce a lush lawn.

Having said that, you'll still need a ground cover. Pachysandra terminalis (Japanese spurge) is a reliable player. It fills in nicely yet isn't invasive, remains evergreen in this area and does a tremendous job anchoring the soil. Vinca minor (periwinkle) will serve a similar purpose and flower nicely in midspring.

Ajuga

It's important to note where your shade is coming from. If it's caused by deciduous trees like dogwoods, maples or oaks, then shade is a concern for only the part of the year when the tree has leaves. You can take advantage of the sun exposure before the tree leafs out and grow some sun-loving early-season perennials there. Try tulips and daffodils to brighten up the spot.

Before beginning any garden project, you should always test your soil's pH. The results will tell you which plants are suited to the site as well as guide you in amending the soil, if necessary. Test kits are widely available online and at local nurseries, and the Cornell Cooperative Extension will test your soil and make amendment recommendations for a nominal fee. (Call 516-228-0426 in Nassau; 631-727-7850 in Suffolk) for information.

Skimmia japonica is an under-used shrub that survives in shade and loves acid soil.

If your soil is on the acidic side, consider shrubs like Pieris (Andromeda), any of the Ilex species (hollies), and Rhododendrons and Azaleas. Skimmia japonica also loves shade and acid soil, and isn't used nearly as much as it should be. Kalmia latifolia (mountain laurel) would make a nice foundation planting. All of these are broadleaf evergreens.

For neutral soils, I love Hypericum 'Albury Purple' (St. Johnswort), which sports bright yellow flowers and red berries on a low-growing shrub with purple-tipped green leaves. It's indicated for sun to part shade, but I've had success with it in a mostly shady spot. I'm also fond of hydrangeas, which do very well in the shade.

Some varieties, such as the aptly named 'Endless Summer,' offer a full season of blooms. Abelia x grandiflora (glossy abelia) will serve you well, too. Boxwoods, both common and Japanese, will thrive, as will any of the yews and Prunus laurocerasus (cherry laurel).

If you're looking for annuals, you can't go wrong with impatiens or wax begonias. Coleus is a shade-loving foliage plant that's available in many different colors, and flowering tobacco (Nicotiana alata), which tolerates partial shade well, grows up to 4 feet tall and gives off a delicious jasmine scent.

As far as perennials go, you can't go wrong with Phlox divaricata (woodland phlox). Its blue, lavender or white blooms sit atop small green leaves in late spring, and it's a generous reseeder.

Heuchera (coral bells) blooms in summer with tall spikes of tube-like flowers rising above a mound of colorful foliage. Both perform well in partial shade, as do Echinacea Purpureas (purple coneflower), Aquilegias, Digitalis (foxglove), Astilbes, Campanulas, Lobelias and many lupines. Hellebores will flower in the winter, and Ajugas and ferns both have it made in the (deep) shade.

Mid-February to mid-April is the ideal time for pruning most woody plants, both because they're dormant and because you can better see what you're doing when your view isn't obstructed by leaves. It's also the period of most rapid plant healing, called compartmentalization.

If you're unable to prune now, wait until July, which is the next-best time to prune. (For the record, late spring is the absolute worst time to prune. Removing new spring growth at a time when the plant is vulnerable means it won't be able to compensate adequately. Also, photosynthesis is beginning, and the plant is at its weakest.)

I was fortunate to learn about pruning, defined as the selective removal of plant parts for a purpose, from Richard Weir III. For the unindoctrinated, Weir was the program manager for horticultural and environmental issues for the Cornell Cooperative Extension of Nassau County. He's also a pruning expert and co-author of "Pruning: An Illustrated Guide to Pruning Ornamental Trees and Shrubs."