Lisa Halvorsen, Extension Associate Professor
University of Vermont
You don't have to glance at a calendar to realize that June marks the gateway to summer. Although the official start of the new season--known as the summer solstice--isn't until the 20th of the month, by that time most gardens are planted, weeding and watering are regular chores, and harvesting of early season crops like lettuce and peas is already underway.
Of course, if weather or other obligations kept you from planting on schedule, it's still not too late to put in most crops. That's the beauty of June. You also can start second plantings--or even your first--of bush beans, sweet corn, and salad crops this month.
If you got your garden in early, thin your carrots, beets, radishes, and lettuce this month. Thinning prevents competition between plants as they grow. It also provides better air circulation between plants. This, in turn, helps prevent foliar diseases.
Asparagus, which should be done producing by now, needs special attention for a good crop next season. Once the harvest has ended, spread about three pounds of fertilizer (5-10-10 or the equivalent) or two bushels of well-rotted compost per 50 feet of row.
Mulch heavily with straw or leaves to keep down weeds. But don't cut off the ferns until September as they are harvesting the sun to make carbohydrates for next year's crop!
Your garden also will need to be mulched this month, usually after mid-June. By then the soil has warmed up enough so you can lay down a three- to four-inch layer of straw, weed-free hay, or bark. Or use black plastic. Mulch smothers weeds while retaining moisture and nutrients in the soil. Just be sure to weed the area well before mulching.
Potatoes need to be hilled about six to eight weeks after planting. If you got them in the ground in April, as many Vermont gardeners do, then June is the month to hill them for the first time--just as soon as the plants start peeking through the soil. Hilling loosens the soil, giving the developing tubers room to grow. It also prevents the potatoes from poking through the ground and turning green (and bitter) from the sun. You will need to hill again in a few weeks.
In the flower garden, pinch back chrysanthemums to encourage them to grow in a compact shape and bloom more prolifically. Start pinching back the tip of each shoot when the plants are four or five inches tall. Pinch back the plants every time the side shoots grow four or five new leaves--about once every few weeks. Stop after July 1. Pinching back mums after early July may delay flowering.
Plant summer-flowering bulbs like tuberous begonias, caladiums, dahlias, cannas, and gladioli in well-drained soil. Most bulbs don't like wet feet, so avoid water-logged soils and wet spots. For best results, know the needs of your bulbs. Gladioli, cannas, and dahlias, for instance, thrive in full sun and rich, well-drained soil. Caladiums, tuberous begonias, and achemenes prefer shade and soil that is high in organic matter.
Other activities for June: check vegetable crops for flea beetles, Colorado
potato beetles, and other insect pests; stake peonies; move houseplants
outdoors for the summer.