University of Vermont Extension 
Department of Plant and Soil Science

Summer Article


By Dr. Leonard Perry, Extension Professor and
Lisa Halvorsen, Garden Writer

August is harvest time, not just for vegetables, but for herbs you grew in the garden. When to harvest depends on what plant part you are picking, and its intended use.

Herbs should be harvested when flavor and aroma oils are at their peak. The leaves of parsley, mint, oregano, and basil, for example, can be harvested throughout the growing season. Flowers from borage and chamomile should be picked before full flowering.

For freshness and flavor, the best time to harvest herbs is always in the morning just after the dew dries. If you aren't planning to use them fresh, dry herbs on a clean window screen in a shady location for 10 to 14 days.

Leafy herbs with long stems can be tied in bunches and hung upside down from the rafters or an indoor clothesline to air dry. Just rinse to remove dust and dirt, shake off excess water, and clip off diseased or dead leaves before drying. A few culinary herbs, including dill, can be chopped and frozen although basil, another popular herb, will turn black if frozen and so is best dried for future use.

After daylilies, peonies, bearded irises, and other herbaceous perennials stop blooming for the season--usually by late August--it's time to dig and divide the plants, if needed. First prepare the new flowerbeds, turning the soil with a spade or tiller, and working in adequate amounts of compost or fertilizer.

Cut the tops back to four inches. Then, using a sharp knife, divide the clumps, leaving at least three to five healthy buds, "eyes," or shoots per plant. Carefully replant in the new location, watering thoroughly to get the plants off to a good start. Be sure to plant the new roots at the same soil depth as the parent plant.

Once your peas and other early garden crops have stopped production, remove them from the garden. Getting these plants out of your way will make it easier for you to care for remaining vegetables and reduces the chance for diseases to get going on aging foliage. It also opens up space for planting later-producing crops or cover crops, such as oats, that need an early start if they are to put on significant growth before frost. Get a head start on fall clean up by removing stakes and markers no longer in use this year.

Don't let the garden get weedy, even if the season is winding down. Pulling the weeds before they have a chance to flower and go to seed will reduce the number of new weeds next year. Do not discard weeds in the compost pile as some weed seeds will survive the winter and will germinate next year when the compost is used.

Continue to be vigilant about pest control. Slugs and snails have been a particularly bad problem in gardens and flowerbeds this year due to heavy rainfall. If you have a home orchard, pick up and destroy all fallen fruit around trees to prevent pests from overwintering and causing problems next year.

If you have been trying to the grow "the great pumpkin" for an end-of-the-summer fair or Halloween, early August is the time to do some pruning and fertilizing. Start by taking off all but one or two pumpkins from the vine. Pinch the ends off the vines to encourage development of the fruit already set on the vines.

Apply liberal amounts of composted cow manure or a diluted plant fertilizer around the base of the plant. Keep the area free from weeds to prevent competition for nutrients and moisture. Mulching with straw or leaves can help. You also may want to spray the foliage with an appropriate fungicide to prevent mildew from reducing the vigor of the plant.

In late August, after the harvest is over, prune raspberry bushes. Removing old canes gives the new ones room to grow. Do NOT fertilize at this time as this will encourage new growth that will only be killed by fall frosts.

Although providing adequate water for gardens has not been a problem in most of northern New England this summer, you may need to check hanging plants and container-grown plants on an almost daily basis to make sure that they have received enough moisture. Potted plants tend to dry out more quickly, and those placed under eaves and other protected locations may just not be getting enough water from natural rainfall. Wind and sun also dry out hanging baskets more quickly than other container plants.

Don't just touch the surface. Push your finger into the soil, about two inches down to determine if enough water is reaching the roots. Water thoroughly.

Other activities for August: harvest rose hips for tea; reseed bare patches in your lawn; plant ornamental kale and cabbage for fall color. This also is a good time to visit perennial nurseries to buy late summer blooming perennials. For a list of places in Vermont, visit

Return to Perry's Perennial Pages, Articles