Garden Detective

Oh-oh. Yet another it's-too-good-to-be-true green dilemma crossed my desk today. (Read my previous post, Going green isn't black and white for background info.)

With the big push -- and looming legal deadline -- for everyone to start using those spiral "eco-friendly" CFL bulbs, one would think it's pretty safe to assume they're a no-brainer when it comes to the environment. They save a ton of energy and last way longer than standard incandescents. Right?

Not so fast, Kemo Sabe. Those CFLs contain mercury. The same mercury that was used for cavity fillings on people of a certain age, and then blamed for health problems later on. The same mercury that filled glass thermometers that heaven forbid you should bite down on by mistake. And did you ever break one of those things? The mercury separated into little balls and scattered all over the place, forcing you to hold your breath while you tried to pick them up without actually letting them touch your skin.

Aren't light bulbs a lot more delicate than thermometers? In an era when we're trying to phase out the toxic substances, what is it doing in light bulbs?

For the full story -- including instructions for the proper disposal of CFL bulbs, check out New Bulbs Have One Hitch.

According to holidayinsights.com, which apparently puts bizarre holidays on the calendar, the second week in May is officially Wildflower Week. Who knew?

To compensate for the fact that this holiday has eluded me all these years, I'd like to make it up to wildflowers everywhere by giving them a day in the spotlight.

William J. Hamilton, Jr., who was a gardener for 70 of his 82 years, consultant to Cornell Plantations for 30 years, and an emeritis professor of zoology at Cornell University, grew more than 100 different wildflowers in his 3 1/2-acre Ithaca garden. Who better to recommend native northeastern wildflowers to the Cornell Cooperative Extension in New York?

Here's his list, as published by the CCE-Sullolk:

Large White Trillium (Trillium grandiflorum). Waxy, pure white, whorled three-petaled flowers. Bloom period May-June. Petals echoed in the graceful, whorled, trio of low-growing leaves. Neutral to moderately acid soil (pH 5-7); moist or semi-dry. Partial shade or filtered sunlight. Does well on slopes; also can be cultivated on flat land. Prefers canopy of deciduous trees; does less well under evergreens. Takes 4-5 years to bloom from seed. Multiplies readily. (Ohio Dept. of Natural Resources photo)

Foamflower (Tiarella cordifolia). Foam-like spikes of miniature white flowers on stalks up to 9 inches high. Blooms April-June. Plants 6-12 inches. Neutral to moderately acid soil (ph 5-7); moist. Shade. Does less well under evergreens. Light oakleaf groundcover desirable. (US Forest Service photo)

Jack-in-the-Pulpit (Arisaema triphyllum). Stately brown and green-hooded flowers at base of 15- to 20-inch plant. Blooms April-June. Bears scarlet berries in August. Moderately acid soil; moist. Partial shade. Spring Beauty (Claytonia virginica). Delicate, starlike white or pink petals with rose-colored veins on 4- to 6-inch fragile stalks. Blooms April-May. Plants trail on forest floor. Neutral to slightly acid soil; moist. Filtered sunlight. (Photo courtesy Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database / USDA NRCS. 1995. Northeast wetland flora: Field office guide to plant species. Northeast National Technical Center, Chester.)

Wild Ginger (Asarum canadense). Flowers hidden by leaves, maroon with a flush of soft gray green; resemble tiny stone jugs. Plants 4-6 inches. Makes good groundcover because of attractive, long-lasting foliage. Neutral to slightly acid soil; moist. Shade. (Photo courtesy Jennifer Anderson @ USDA-NRCS PLANTS Database)

White Baneberry (Actaea pachypoda). White flowers in tight oblong clusters. Blooms April-early June. Plants 1-2 feet. Waxy white fruits with black eye, borne on red stalks. Neutral to moderately acid soil; moist. Shade or filtered sunlight. (Photo by Jennifer Anderson @ USDA-NRCS PLANTS Database)

Black Cohosh; Bugbane; Fairy Candles (Cimicifuga racemosa). Tall candles of tiny white feathery flowers. Blooms June-Sept. Bold, showy plant 3-8 feet high. Neutral to moderately acid soil; moist to somewhat dry. Partial shade or full sun. (North Dakota State University Cass county Extension photo)

Rue Anemone (Anemonella thalictroides). Fragile flowers in shades of pink and white. Blooms March-May. Plants 4-6 inches. Lacy whorl of small, three-lobed leaves. Neutral to slightly acid soil; moist. Filtered sunlight. (Photo by Jennifer Anderson @ USDA-NRCS PLANTS Database)

Virginia Bluebells; Virginia Cowslips (Mertensia virginica). Nodding clusters of pink buds turn into porcelain blue flowers. Blooms March-May. Plants 1-2 feet. Leaves oval, strongly veined. Nearly neutral soil (pH 6-7); moist. Partial shade. (Photo by Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database / USDA NRCS. 1995. Northeast wetland flora: Field office guide to plant species. Northeast National Technical Center, Chester.)

Herb-Robert (Geranium robertanium). Tiny trumpet-shaped, rose-colored flowers, occasionally white. Blooms all summer. Plants 6-18 inches. Strongly scented, fernlike foliage that turns bronze in fall and is retained throughout winter. Neutral or slightly acid soil; moist or dry. Full or partial shade. (Washington State Noxious Weed Control Board photo)

Hungry for more? Order Common Wildflowers of New York State from the Cornell Cooperative Extension of Suffolk County. (631-727-7850)

It might also be noteworthy to mention that May 1 was Save the Rhino Day. That one just flew under my radar. And in addition to being Bird Day, May 4 is also National Candied Orange Peel Day. But, personally, I'm sorry I didn't know sooner that today was No Socks Day. I would have planned my outfit accordingly.

There's always tomorrow -- Lost Sock Memorial Day.

Lilacs are in full bloom today so what better plant to lauch the Plant of the Week series? (These full-size beauties were photographed along the Old Westbury Gardens lilac walk.)

We're coming up on prime planting season, and my inbox is flooded with requests for plant suggestions and questions about the needs of specific plants. So I've decided to launch the Plant of the Week series, starting today.

Each week, I'll pick something I like -- or a plant you've been asking about -- and profile it here. I'll show you pictures and include care instructions, sunlight requirements and any other pertinent information.

Got a favorite plant, or need some information? Drop me a line and I'll try to cover it.

Lilacs thrive in soil with a neutral or slightly alkaline pH, so your first course of action should be to test your soil with a simple pH test kit, which you'll find at your local garden center. You also can bring a soil sample to the Cornell Cooperative Extension office (visit cce.cornell.edu for details). If your soil is very acidic, add lime before planting.

Select a spot that will supply a minimum of six hours of full sunlight daily, away from downspouts and anywhere else where water might pool. Lilacs do not like "wet feet."

Space them according to their mature size to allow for adequate air circulation and avoid powdery mildew disease, to which they're susceptible. And don't pack them in tightly with perennials; they don't like the competition.

Early spring is the best time to plant lilacs, so you should do so as soon as possible. Dig a hole two to three times the size of the container, mix in some compost and plant at the same level they were at in the pot. Do not fertilize, but water thoroughly after planting, and see to it that they get 1 to 1 1/2 inches of water a week during the first season. Next year, you can give them a shot of 5-10-5 fertilizer in the early spring.

Click thumbnail below to get details about Syringa patula '‘Miss Kim', Syringa x ‘Tinkerbelle' and Syringa microphylla ‘Superba':

Profiles: Favorite dwarf lilacs

Will Wischhusen, far right, and the Botanical Training Group in Great Neck

I spent the morning visiting with the good folks in the Botanical Training Program at North Shore University Hospital's Vocational Training Center. The group, led by Will Wischhusen, comprises aspiring gardeners preparing for careers in the horticulture world.

We talked about soil pH, explored types of liming materials, discussed macronutrients and then played in the dirt, literally.

The group's eight members took turns testing two soil samples -- one from a neglected area in my backyard, the other from directly outside the building on Northern Boulevard in Great Neck. Both were surprisingly nonacidic, with readings of approximately 7.0 to 7.2.

That's some sweet soil, and unless you're planting ericaceous plants like blueberries, azaleas or rhododendrons, it's absolutely perfect. But what if your soil is more acidic, as much of Long Island soil is?

Your first course of action when planting a new area should be to get a soil test. The Cornell Cooperative Extension has walk-in counters located in Eisenhower Park in Nassau and in Riverhead in Suffolk. They'll test your sample for $5. You also can buy a test kit at most nurseries. The advantage to using the extension's service, though, is that it comes with recommendations for adjusting the pH, if necessary.

To get started: Dig down 4 inches and scoop up about 1/4 cup of soil from the area(s) you'd like to have tested. Place it in a zippered plastic bag and run a test.

The pH scale runs from 0 to 14. Readings of less than 7 indicate acid (sour) soil; higher than 7, alkaline (or sweet). Optimum pH depends on what you're planting. Pieris (andromeda), gooseberry, hemlock, creeping juniper, magnolia, pinoaks, white pines and potatoes -- in addition to azaleas, rhododendrons and blueberries -- thrive in more acidic soils. But most common garden plants require a neutral pH of around 7.0, or slightly below. So the next step is determining what pH suites your garden. (For a list of pH preferences of different plants, check out the Cornell Cooperative Extension of Nassau County fact sheet on soil acidity).

Once you know your plants' needs and your soil's reading, you can adjust the pH accordingly, if necessary. That's important because if the pH is off, nutrients won't be available to your plants. They might be in the soil, but they'll be locked up.

Most soil on Long Island is naturally acidic because of the amount of rain we get and because of our humid summers, so lowering pH usually isn't warranted.

Raising soil pH can be accomplished by adding calcium and magnesium to the soil. Both elements are present in limestone. Look for dolomitic limestone or dolomite; calcitic limestone is mostly calcium and contains only a very small amount of magnesium.

Liming materials are available in different particle sizes, which determine the speed of absorption. Like anything else, you get what you pay for. Pelletized lime is the Rolls Royce of amendments. It's fast acting and easy to spread but the most expensive of the group. Hydrated lime also is very fast, but caustic. Pulverized lime is fine and dusty and works fairly fast. Granular is slow acting and inexpensive. Your budget, obviously, but also the size of the area you're treating will determine the type of lime you purchase. If you have a small area and can afford it, go for the pelletized lime. If you're working on a acre of land, let your wallet be your guide.

Lowering soil pH is a very slow process and needs to be repeated ad nauseum. It's a never-ending uphill battle, but if you're growing ericaceous plants, you might have to consider it. Frankly, if my soil weren't suitable for acid-loving plants, I'd plant something else rather than mess with this stuff, but there are instances where it might be necessary, like if your plants are suffering from iron chlorosis (indicated by dark green veins on yellowing leaves.)

Elemental sulfur and ammonium sulfate are two elements used to lower soil pH. Ammonium sulfate also adds lots of nitrogen, which will run off and pollute groundwater something awful, but it gives instantaneous results, so people tend to prefer it. Sulfur can take weeks or months to become effective.

Use extreme care when messing with either of these. If they contact leaves, rinse immediately to avoid burns. And whatever you do, don't over-apply them.

We talked about macronutrients and micronutrients, fertilizers and how some freaky things can end up in drinking water.

In all, I'd say my morning was pretty alkaline.