June Garden Tips


May and early June have seen a string of rainy days in New England.  With that much-welcome rain, unfortunately, has come an equally unwelcome pest:  slugs.  Look over the undersides of leaves in your garden (especially low-growing perennials) and, if you see any slugs, assume there are more lurking in the soil or mulch.  Skip the cutesy internet-fed slug remedies and go for what works: iron-phosphate-based pellets, available under several brand names in most nurseries.  Place them around the base of plants and replenish monthly as long as it keeps raining.

Lilacs (especially) and other spring-blooming shrubs such as rhododendron need to have their spent flowers removed so the plant doesn’t put its energy into producing useless seeds.  Use bypass pruners to snip off the flowers while taking off as few leaves as can be managed.  If your rhodies are getting too big, carefully snap off the new fuzzy leaves that are springing up from the old flower sites.  This removes new growth, will not hurt the plant, and helps to keep your shrub at a size that fits its site, rather than covering the windows and threatening the eaves.

It has been a cooler than normal spring across much of New England.  Don’t let a few warm days fool you into thinking it’s OK to plant ‘hot-weather’ vegetables like tomatoes, corn, squash and peppers.  Until the soil temperature reaches 65 to 70 degrees (depending on the vegetable and variety), resist the urge.  To check your soil temperature, take a standard thermometer and push its base down at least two inches into the soil and leave it there five minutes.  If you want to speed warming the soil, lay down plastic over the area.  Clear plastic allows any weed seeds to germinate and you can easily remove them before you plant.

If you want to keep garden perennials from getting too leggy and flopping over as the summer goes on, cut them back by one-third to one-half now. Mums, phlox, salvias, asters and even autumn joy sedum all benefit from the trimming. You will get flowers slightly later, but there will be more to enjoy — plus, you won’t have to spend time staking them.

Peonies are in the midst of their annual show. Many peonies bring fragrance to the garden along with large splashes of color. If you didn’t install peony rings or cages before the plants grew too large, use bamboo stakes to tie up individual blooms. The large flowers often snap over from their own weight. Remove the dead flowers when the season has passed and you’ll have a lovely shrub for the remainder of the summer. And, don’t fret over the ants you see on the buds. They are not harming the flowers at all. If you want to bring peonies in the house, either cut them when the bud shows color, but before it opens, or gently place the peony flower in a bucket of water. After several minutes, all of the ants will have ‘deserted ship’.

If you have deer in your neighborhood, protect your delicious shrubs and perennials now. Deer will browse on everything. Commercially available sprays put down vile-smelling concoctions of putrefied eggs and garlic. Those sprays become odorless to us when they dry, but the nasty taste remains to any creature that nibbles on leaves. A monthly spraying of the garden will teach deer and rabbits to stay away from your plants.

The days and nights are now warm enough to move houseplants out for a summer vacation. As you place them outside, start in the shade of a porch or tree. Move them very gradually into more sun to avoid sun scald or even death. Wind and heat combine to quickly dry out containers so check frequently to ensure that your houseplants have sufficient water. If you choose to replant now, remember the new pot should be no more than two inches larger than the old.

Good news!  The wet spring has done more than refill our reservoirs.  It also seems to have activated a fungus that naturally keeps gypsy moth caterpillars in check.  This should mean less damage than last year, and with luck, fewer caterpillars again next year.

Be very aware of the deer ticks that are everywhere–or so it seems.  It’s not just Lyme Disease anymore. Every year medical researchers link ticks to another serious illness. Use sprays effective against ticks before going outside, check yourself (and your children) daily and call your doctor if you think you may have been bitten.