June Gardening Tips
With June comes the warm weather and with it the weeds and garden pests. Growth is in full swing. This month, focus on keeping the garden tidy to prevent disease and keep it looking its best.
Watch Out for Cutworms
Cutworms are fat, gray or dull brown, 1-2 inch long caterpillars that come out at night and chew though the tender stems of new seedlings. To protect young plants, use collars to prevent cutworms from reaching your seedlings. Try these ideas:
– Wrap the stems at transplanting time with 4 or 5 layers of newspaper strips 2 inches high – push them into the soil
– Make 2-inch high barriers out of stiff cardboard, toilet paper rolls or paper towel rolls, old milk cartons, or tin cans. Push them firmly into the soil.
- Weed, weed, weed! Here are our recommended weeding tools >>
- Check for pests and other problems and treat as necessary. Make sure you properly identify any “pests” before trying to eliminate them – some may actually be beneficial.
- Mow lawns regularly. For best results, keep grass at 2-2½ in. height and leave grass clippings on the lawn (this improves the availability of nitrogen and provides organic matter to support plant growth).
- Water as necessary. Do not let your plants wilt. Check our guide to the Best Garden Hoses >>
- Prune all shrubs and trees to remove diseased, dead, weak or crossing branches. This is a gardening task to do each and every month.
- If you grow roses, spray them weekly with a solution of baking soda and water to control fungus or powdery mildew (or use my favorite organic method, GreenCure fungicide). Pick off and discard any leaves with black spot and avoid watering the foliage so that black spot won’t spread. Feed and mulch your roses. Spray aphids with a strong jet of water and pick off Japanese beetles (don’t use traps unless the entire neighborhood does or they’ll all end up in your yard!).
- Deadhead all old flower blooms to encourage new flowering.
- Prune evergreens and evergreen hedges. Finish pruning spring-flowering shrubs. Check our review of the Best Pruning Shears >>
- On June 14th (Flag Day) apply a grub and surface insect control for your lawn, such as Merit® (unless you prefer organic methods).
- Stake or cage tomatoes and provide support for climbing veggies (e.g., beans, cucumbers).
- Pinch back late perennials to keep them short and full (e.g., asters, phlox, helenium, mums). Without pinching, they have a tendency to get tall and floppy – not a very attractive look.
- Deadhead rhododendrons, lilacs and perennials after flowering.
- Water your lawn if there is less than 1 in. of rain per week. Tip: 1 inch of water will fill a tuna or pet food can to the top.
- If deer are a problem, continue to apply deer repellents.
- Mulch planting beds (if you haven’t already done so) to suppress weeds and retain moisture.
- Set supports for floppy or climbing plants.
- Many plants benefit from fertilization this month. Fertilize roses after peak bloom (I use Magnum rose fertilizer) and give a good shot of quick-acting fertilizer to annuals, container plants, and vegetables. Also fertilize any remaining spring-flowers bulbs as they die back. If you’re not sure whether your garden needs supplemental fertilizers, have a professional soil test done.
Nice to Do
- If you live in cooler climates, harvest cool-weather veggies (like lettuce, spinach and radishes).
- Sow seeds of heat-tolerant vegetables (like tomatoes and peppers) and consider adding a second crop of onions, lettuce, and beans.
- Dig and divide early-blooming perennials after flowering.
- Finish planting and transplanting perennials.
- Add to, aerate and moisten compost pile to speed decomposition. Learn more about composting here >>
- If you plant to plant summer annuals, now’s the time to finish that, as well as planting summer-flowering bulbs such as cannas, gladiolas and dahlias.
- Tender caladium and tuberous begonias can be planted this month in shady spots.
- Sow fast-growing annuals, such as marigolds, zinnias, and cosmos, directly in the garden.
- If you didn’t deadhead annuals and perennials last year, you may find “volunteer” seedlings growing throughout the garden. Move them to where you’d like them to be.
Note: The June gardening tasks described here are for gardeners in zone 6. Tasks may be done earlier, or later, if you live in warmer or colder areas. I’ll be adding more information over time showing tasks in other areas of the country. If you have suggestions, please share them in the comments below!