It's Time to … What to tackle in your garden this week

Mulch mindfully. If you have newly planted trees or even old ones, consider mulching them to protect from mowers and weed whackers near their trunks. This is the main cause of tree death. Make sure mulch is not up against the trunk; this causes the bark to get moist and rot, which promotes disease. Keeping the trunk exposed encourages good tree health and stability. Mulching properly helps reduce temperature fluctuations in the soil and retain moisture. Grass also takes valuable water from the tree's root system. For good mulching information, go to www.treesaregood.com/treecare/mulching.aspx.

On your mark ... You'll face stiff competition at plant sales at local arboretums and botanic gardens this spring, and here's why: The plants are fantastic. If you're looking for unusual shade plants, chances are good that Scott Arboretum in Swarthmore will have a special epimedium or a 'Gold Heart' bleeding heart. Trillium, you say? Bowman's Hill Wildflower Preserve in New Hope will certainly be able to help. Greater Philadelphia Gardens, a consortium of 28 gardens in the region, has a super 2012 Guide to Spring Plant Sales. You can download it at greaterphiladelphiagardens.org/.

Build with bamboo. Find someone with a stand of invasive bamboo and ask if you can cut a few canes to make trellises and frames for climbing pole beans and tomatoes. Bamboo is lightweight, strong, and flexible, a perfect support material for the garden. Do this before planting and you'll be ahead of the game. I can't wait to start building! Find a useful how-to guide at www.finegardening.com/how-to/articles/build-a-bamboo-trellis.aspx

Gently tug. That's the best way to check if your rhubarb is ready to pick. Remove blooms to prevent the plant from going to seed; seed takes vital energy away from new leaves. Rhubarb comes in pink, red, green, and variations in between. Deeper red rhubarb is usually tarter than the green-stemmed variety. And remember: Only the stems are edible. Leaves are poisonous, but they do have a beneficial use. They have a natural insecticide in them, so when I cut the leaves off the stems, I like to lay them around the plants to keep down weeds and repel insects.

Rake those holly leaves. If you have a holly tree, as I do, you'll notice that it's beginning to shed last year's leaves. Raking them up will keep your tree healthier, especially if you've had problems with leaf miners, those tiny flies whose larvae like to burrow into leaves, leaving squiggly lines behind. Raking will reduce the chances of reinfestation. Trees get infested when tender new leaves are emerging in spring. Gather collected leaves in a black trash bag and let the bag heat up for several weeks to kill the insects and their larvae. Then the leaves can be ground up and used for mulch.

Snap, don't cut, those asparagus. Look for spears with nice, tight tips. If the tip looks loose, don't pick it; this means the spear is already beginning to leaf out. With warm days coming, check daily. The best way to pick asparagus is to find the easiest breaking point toward the base of the stem. It should make a clean, snapping sound. Freshly picked asparagus is delicious raw, but don't eat all of it in the field. Store some in tall containers with about a half-inch of water and refrigerate. You can also freeze them.

Don't go so low. Bad things can happen to your lawn if you mow it very short in spring. You're setting the stage for problems later in the season, when the days get hotter and weed seeds work their way onto the soil surface. Better to keep your lawn at three inches or longer. The leaf blades shade the roots below, keeping them cooler and also starving weed seeds of light. Most need full sun to germinate. With a higher cut, your lawn will also be healthier during periods of drought because the roots are not exposed.

Break time for scapes. The garlic you planted last fall may be developing scapes, which are the stalks that contain the flowers. Not all garlic develops scapes, but if yours does, break them off below the bloom area, which is defined by a thick purple line on the stem. Removing these stalks helps the plant concentrate all its energy on developing a larger head/bulb. Scapes are delicious in stews, stir-fry, and other dishes that you would typically add garlic to. The garlic heads will be ready in June.

Eva Monheim is a certified arborist, master floral designer, and full-time lecturer in horticulture at Temple University Ambler; she is also an instructor at Longwood Gardens in Kennett Square. She can be reached at emonheim@temple.edu.