June gardening checklist (© Emilio Ereza/Pixtal/agefotostock)

There are plenty of reasons to celebrate June, but let's start with just one: It's summertime.

The solstice isn't until June 21, but not all plants know that.

Lots of gardeners have already begun their summer planting and maintenance.

A good way to start is to plant extra bulbs now for a burst of brightness later in the summer, when some of your early favorites have begun to fade. Dahlia, gladiolus, canna, crocosmia, tuberous begonia and tigridia are all good choices for a touch of garden drama.

Now that the weather is warmer, you can lower your water bills and impress your neighbors by watering at cooler times of day to prevent quick evaporation.

In many climates, early June isn't too late to put annual seeds or seedlings in the ground. Plant sunflower, marigold, cosmos, sweet alyssum and zinnia. You can also plant seedlings of geranium, impatiens, petunia, coleus and Madagascar periwinkle; by now, the ground in most regions is ready for even the most tender vegetables and flowering annuals.

Annuals that have already bloomed should be deadheaded when the flowers fade.

Read:  June home-maintenance checklist

'Color spots'
For splashes of color in early summer, select bright nursery annuals already in bloom. They're a great solution for the time-challenged gardener, and it's more pleasant doing "dirty work," such as dividing perennials and planting seeds, when you're surrounded by chocolate cosmos and scarlet impatiens.

Plant color spots of annuals — usually sold in 4-inch, 6-inch or 1-gallon pots — to accent your garden with instant brightness. Be sure to water plants before removing them from pots, and water again after planting.

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Perennials
Perennials are June-perfect planters.

Plant flowering perennials of all kinds for late-spring, summer and fall blooms: Oriental poppy, foxglove, salvia, aster, columbine, delphinium, feverfew and heuchera are but a few. Add lamb's ears, sage or dusty miller for foliage.

Perennials that flowered in the spring can be dug up and divided now to prevent overcrowding. Divide irises (whose rhizomes will need to be cut apart), Oriental poppies, primroses and Doronicum daisies.

Starting now and over the next few months, you can also free those perennial seeds from their packets and get them in the ground. Pinch off spent blooms to keep flowers coming.

Lawn care
The contest for greenest lawn on the block is far from over. By now you've surely been out mowing and have possibly reseeded, so keep up the good work.

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  • If your lawn needs aerating, it's still not too late to perforate away.
     
  • Overseed or reseed those stubborn scraggly spots.
     
  • Fertilize now, if you didn't do it in April or May.
     
  • When it comes to watering, even if the heat is on, think conservatively: Your grass may take on a tawny tone, but it will spring back as the weather becomes cooler and moister.
     
  • After mowing, leave grass cuttings on the ground to recycle all those good nutrients.

Vegetables and herbs
In most climates, all herbs can be planted this month. And now's the time to get veggies in the ground that you can enjoy on your table in the months to come.

  • The start of summer also means it's your last chance for sowing squash and cucumber seeds.
     
  • Corn, eggplant, peppers and tomatoes should also be planted as soon as possible.
     
  • To expand your harvesting season, start planting successive crops of carrots, lettuce, spinach, chard, kohlrabi, beets, parsnips, radishes, turnips, bush beans and peas.

Fertilizing
If you see signs of winter's ravages on trees, shrubs or perennials, run — don't walk — to give them extra food or correct problems such as mildew, black-spot and aphids.

  • All plants that are having a hard time springing back from winter should receive a mild feeding this month.
     
  • Fertilize roses now and each month through the summer.
     
  • Allow spring-flowering plants to bloom before you feed them.
     
  • Hold off on fertilizing tomatoes until their first fruit has set.

Permanent plants
In many areas, June is a good time for planting trees, shrubs, vines and ground cover. Check with your local extension agency or consult a reliable gardening book to see which species are best suited for early summer planting in your zone.

Fruit trees
Take care of fruit trees now to make sure you get your sweet rewards later in the season.

  • Thin Asian and European pear trees heavily now.
     
  • If it's a "light year" for any of your apple trees, avoid pruning them — but the heavier fruit bearers should be thinned lightly after their unpollinated fruit has dropped. Remove one apple from triple and double clusters to encourage the growth of larger fruit.
     
  • If you find tent caterpillars in tree branches (they're especially fond of crabapple and fruit trees), prune out the limbs and destroy the cocoons.

Pest control
Don't let down your guard yet with slugs and other garden pests.

  • If you live in a moist climate, you'll probably notice that slugs have been drawn out by spring rains. Now's the time to put out shallow bowls of stale beer or sprinkle slugs with salt.
  • Stay ahead of aphid invasions by hand-wiping foliage, giving them a strong blast with a hose, or soaking them thoroughly with insecticidal soap. Repeat the treatment in five to seven days if you see signs of new hatchlings you might have missed.
  • You can also use soap on plant bugs that are pestering your shrubs, perennials or fruit trees.