Avid gardeners know the gardening season isn’t over even as summer is winding down. In fact, it seems there’s just as much to do as in the spring, if not more! Here are a few tasks we make sure not to miss in the gardens at Horsford Gardens and Nursery:
The Vegetable Garden
After your final harvest pull up annuals such as tomatoes, peppers, and beans. Remove leaf litter to help prevent the wintering over of leaf-borne diseases. Leave root vegetables for harvesting later, and brussels sprouts until after the Thanksgiving meal. You can also leave kale plants, as they tolerate some frost.
Topdress cleaned beds with a light layer of compost. Once the bed is cleaned and prepped, it’s good to plant a cover crop to prevent erosion and weeds, to break up compacted soil, and to work into the garden later.
Some gardeners rototill their gardens in fall with the belief this brings insect eggs to the surface to perish. The following season you may see less bug issues but there is no guarantee.
Herbs and Annuals
Annual flowers and herbs last one season. After your final harvest and seed gathering pull up the plants and compost them. Woody perennial herbs such as thyme, savory and lavender don’t die to the ground so cutting them back late in the season can kill them. Herbs such as tarragon and lovage can be cut to the ground.
A perennial is a non-woody plant that dies to the ground each fall while the roots persist through winter. New growth emerges in spring from the crown. Cutting back the entire perennial garden has become standard practice in recent years. There are pros and cons to this.
Pros: It looks tidy. You get a jump on spring garden chores. Rodents cannot hide under stems and dead foliage, or live off the crowns of plants such as hosta, geraniums and daylilies.
Cons: You’ve made the garden bare and unprotected from winter’s elements. Stems left standing will trap blowing leaves and falling snow. The layer of leaves and snow helps maintain a constant temperature and prevents intermittent freezing and thawing that can kill plants. Decomposed leaves are wonderful soil builders. Birds live on bugs in the summer, and seeds and berries all winter. Leaving your grasses and coneflowers standing provides a natural food source all winter.
Cut back hosta leaves in early October before they turn to mush after a frost. Set out rodent traps beginning in August when critters are preparing their nests for the long winter.
If you have newly planted young trees, especially fruit trees, wrap plastic tree guards around the trunk from the ground up. Tuck the bottom end into the ground. This is your best method to prevent mice and voles from girdling the tree, and will be the best $2 you spend on your landscape.
Prune plants that bloom on new wood in late summer or fall. Hydrangea paniculata, in particular, benefit from a sharp pruning that helps strengthen branches.
Shrubs that bloom on old wood, such as lilacs, should not be pruned in the fall. Doing so will remove all of next spring’s flowers.
Newly planted shrubs (and trees) should be well watered right up to frost. If winter is light on snowfall and spring is light on rainfall, resume supplemental watering in the spring.
Plants begin to “shut down” and prepare for dormancy in late August when the days shorten and evening temperatures cool. You should stop fertilizing and adding compost to plants at this time. Late season feeding can trick a plant into growing, especially if we are treated to an Indian Summer.