June Gardening Tips
June marks the beginning of irrigation season unless May was unusually dry. Our August tips page has some detailed information on good watering techniques, and we encourage you to have a look there. Aside from that, know that June watering can be random; we might get shower after shower followed by a series of dry, hot days. Be ready to water, but do not do so unless the soil/plants are ready for it. Recent plantings always need more water than established plants, so make adjustments as necessary.
Mosquitos can start to be a pest now. Avoid standing water, or change it quite regularly. If that is impractical (ponds, etc.), consider mosquito dunks or another appropriate product to kill the larvae.
June can mean good planting weather. If we have an excessively wet spring, this might be the first time your clay-based soil is actually drying out and becomes easier to dig. It is a fine time for planting almost all types of plants, if you or someone is going to be around to water this summer. You cannot leave a June-planted tree, perennial, or vegetable bed to go without water during the summer that follows.
Our stock of annuals is at its peak at this point. All warm season annuals should be available, including sunflowers, zinnias, vines, and other heat lovers. Clean out those empty or tired pots and get yourself some color. Note that pansies often start to look pretty bad as the season gets hot, so many gardeners replace them in June with summer bloomers.
Our stock of perennials should be at or near its peak in June. While the earliest bloomers (candytuft, bergenia) may be out of bloom, they may still be available for purchase. Also, the summer bloomers are ready to go home with you; get those crocosmia and daisies now.
Many garden insect pests are problematic in June. Caterpillar damage may begin to get bad, and aphids and slugs may reach significant populations. Thrips and whiteflies may appear on susceptible flowers, and flea beetles and cutworms can be troublesome to vegetables. If you have a pest, try to identify it correctly so that you can make the best decisions about control methods. We can, of course, help with identification and recommend controls, whether they are natural predators, insecticides, or waiting the problem out.
Get those begonias and dahlias planted if you are still hanging on to them. Summer-flowering bulbs should be in the ground now, so plant ASAP if you have not already done so.
Finally, danger of frost is almost assuredly past… so get those crops going! Tomatoes, beans, melons, squash, peppers... these and more are great to plant in June. As always, please reference our veggie calendar for planting time recommendations. Remember that most fruiting veggies (like many of those just listed) enjoy fertile, loose soil with lime and fertilizer added.
If you did an early to mid spring crop of greens, they should be harvestable about now. This might be your last good chance for starting another crop of these, as greens can be challenging to grow in the heat of summer. If they ‘bolt’, or bloom, the flavor of the leaves turns bitter.
Early planted cole crops (cabbage, broccoli, etc.) may be harvested as soon as ready. It is best to wait to replant these vegetables until late summer or early autumn. Avoid planting them now because summer’s heat diminishes them, and you will have a meager harvest. These truly are cool-weather crops.
If the garlic that you started earlier this year or last year starts to flower, break off the stems. Allowing them to develop can drain energy, and therefore harvest, from the bulbs themselves. Try to be a moderate waterer, as inconsistent watering is one of the causes of premature flowering in this case.
You can still start new grass seed in June, but watch the water needs carefully. If it gets hot and dry soon after germination, the grass may fail. Sod is a little easier this time of year, and fights back against the weeds better.
If you have not done so recently, go ahead and feed your lawn. While it is not generally recommended to feed lawn in late July to August, now is still part of the natural growing season for lawn grasses.
Watch for those thistles and dandelions, now that the days are getting warmer they will start breeding all the faster. Dandelions can take dry conditions better than lawn can, so be a consistent waterer. Also, dandelions thrive in calcium depleted soil better than lawn; a good reason to keep up with lime applications.
Crane flies and other grubs are active this time of year and can be the culprit if you have a patchy lawn. If so, dig up a section of it, down to a few inches, and look for any ugly grubs between ½ and 2 inches long, white or gray. If so, treatments with insecticides or beneficial nematodes can often help. As always, use any insecticides according to label directions, and make sure to get an appropriate one (we can help you select the best one).
Feed your roses and other summer flowering shrubs. Roses may be showing some fungal problems such as black spot or powdery mildew, so watch for those and treat where appropriate. The first part of June is usually when roses come into bloom, so it can be a great time for viewing or shopping for them.
If the weather has been wet, you may see significant shothole fungus on your cherries, plums, and their relatives. This is a fungus that only spreads when the leaves are moist, but it can spread quickly if June is wet and you do not treat for it. Feel free to inquire about an appropriate fungicide for this or other similar troubles.
It is too early for summer pruning of fruit trees, as truly dry weather is desirable for this. Also, most shrubs should not be pruned now. The only exceptions would be any rhododendrons or their relatives that are just finished flowering. Note that you do not want to wait into summer for this, it should be done promptly after flowering. The reason why is that rhododendrons form next year’s flower buds during the current summer/autumn growth season, and we do not want to remove those by pruning.
Apple maggot flies (the adult) become active as temperatures warm, and start laying their eggs on forming fruit. These are one of the types of “worm” in apples. If you have had such a problem in the past now is the time for hanging traps to monitor for their presence. Note that traps are generally not a remedy by themselves; they are usually accompanied by timely spraying once the pest is detected on the traps.
Click photo to play video Videos will load automatically. Visit the GardenTime TV website for more GardenTime videos.