Wednesday, June 29, 2016

Late-Summer Flowers: Annuals ensure color throughout the season

There are a few perennials that save their big show for the end of the summer. Among them: Rudbeckia (yellow flowers) and helenium.
The ultimate perennial garden. It's not difficult to bring that vision to mind. For me, it's a classic English border, with iris, lupine and poppies, that continues blooming right into the fall, with wave after wave of color and form: foxgloves, roses, delphinium, dianthus, hollyhocks, lilies and more.
The truth is, since I don't live in the British Isles or the Pacific Northwest, making that vision a reality in my own garden is all but impossible. Bloom time in most American perennial borders runs from late May through early July—a glorious but short 5 or 6 weeks. By late July, most perennial gardens are past their prime and look pretty dull for the rest of the season.
Fortunately, there are many perennials that bloom in late summer, including coneflower, asters, mums, Russian sage, cimicifuga, sedum, rudbeckia, and phlox. But I've found annuals are the real key to summer-long color.
Unlike many perennials, most annuals thrive in summer's heat and once they get started, will keep blooming right into early fall. With a little planning you can create annual-perennial partnerships that will keep your flower gardens looking terrific for a full 5 or 6 months.
I'll provide a list of my favorite perennial companions, but first, here are a couple things to keep in mind:
Heliotrope thrives in the cooler temperatures of late-summer and early fall.
1. Choose the right style of annuals. You don't want plants that are too billowy or too bold in flower or foliage. The best companions are vase-shaped, old-fashioned flowers with a casual form. The types of annuals that work best are those that weave among the foliage of your perennials. Good examples include verbena, nicotiana, salvia, diascia, and heliotrope.
2. Choose heat-tolerant annuals. Unless your perennial border is in the shade, you’ll want to select sun-loving, warm-weather plants such as ageratum, alyssum, cleome, morning glory, browallia, nicotiana, salvia, verbena and matricaria.
3. Don't neglect the tropicals. There are many fabulous heat-loving plants from zones 8 and 9 that can be used as annuals. Though many of these are quite large and possibly too bold to blend into the average perennial border, you may want to find space for them. Good candidates include canna, elephant ear, ginger lily, Mexican sage, and the many varieties of plectranthus.
I plant most of the annuals right into my perennial borders in the spring. Others get planted in the cutting garden and get moved over as needed to fill those inevitable holes that occur as the season progresses. You need to choose a rainy day to move these plants, which may already be in flower, but if you soak them well ahead, and keep the root ball intact, they should survive the move just fine.
Here are the annuals I plant in my perennial gardens:
Matricaria: I can't imagine my garden without this refreshing blast of white. I grow matricaria from seed since I've never found it offered in nurseries.
Mums: Some varieties will overwinter here in zone 4, but I usually treat them as annuals. Plant a couple fist-sized clumps in the spring. By fall each plant will give you dozens of long-lasting blooms. For good late season color, keep your mum plants pinched back until early July.
Coleus: There are hundreds of incredible colors of coleus to choose from. Pinch them back to keep them bushy and remove the flower heads as they appear.
Anise Hyssop: I've interplanted this for so many years that it now self sows and I just dig up and move the plants where I want them. It's not exceptionally showy, but has good foliage and form, with fluffy purple flowers in August and September.
Salvia horminium (Salvia viridis): This is a great plant with purple, pink or white bracts. Like a poinsettia, it's the top leaves that provide the show, not the flowers. Salvia horminium looks good right through late fall.
Impatiens: I plant pink ones along the front of my long perennial border. The border faces north, so the perennials provide them with some shade. Impatiens bloom until frost, and the dependable splashes of pink pulls the border together.
Cleome: I plant these at the back of the perennial border. The four-foot high plumes provide both height and color from July through September.
Ammi majus: Also known as Bishop's weed, this plant looks like an airier version of Queen Anne's lace. Sow it successively from June through July since the plants fade after a couple weeks of blooms.
Sanvitalia procumbens: This low, spreading plant looks like a miniature black-eyed Susan. It loves the heat, and works well in rock gardens or at the front of a sunny border.
Salvia farinacea: The purple 'Victoria' has rich green foliage and spiky blue flowers. Its form is a bit stiffer than most good perennial companions, but I find it makes a great mid-border filler.

A Guide to Successful Pruning, Pruning Evergreen Trees

Anatomy of an Evergreen Tree

Evergreen trees have leaves that persist year round, and include most conifers and some broad-leaved trees. Evergreen trees generally need less pruning than deciduous trees.
Conifers are distinguished from other plants by their needle or scale-like leaves, and their seed-bearing cones. Because conifers have dominant leaders, young trees rarely require training-type pruning. The leader is the vertical stem at the top of the trunk. If a young tree has two leaders, prune one out to prevent multiple leader development. Selective branch removal is generally unnecessary as evergreens tend to have wide angles of attachment to the trunk. 
Evergreens are grouped on the basis of their branch arrangement. Pines, spruces, and firs have whorled branches that form a circular pattern around the growing tip. The annual growth of a whorl- branched conifer is determined by the number of shoots that are pre-formed in the buds. Whorl-branched conifers usually have only one flush of growth each year in which these pre-formed shoots expand into stems that form the next whorl.
The second group of evergreens are those with a random branching habit. Yew, arborvitae, cedar, false cypress, and juniper are all random-branched species.

What to Prune

Corrective pruning for evergreen trees consists mainly of dead, diseased, or damaged branch removal. Remove dead wood promptly, by cutting dead branches back to healthy branches. When pruning diseased branches, make thinning cuts into healthy wood, well below the infected area. Thinning cuts remove branches to their points of origin or attachment. Disinfect tools between each cut with products such as "Lysol," "Listerine," or rubbing alcohol. Tests have shown that "Pine-Sol" and household bleach are highly corrosive to metal tools. 
Allow evergreen trees to grow in their natural form. Don't prune into the inactive center (no needles or leaves attached) of whorl-branched conifers because new branches won't form to conceal the stubs.
When a tree's leader is lost due to storm damage or disease, replace it by splinting to a vertical position the upper lateral on the highest branch. Prune all laterals immediately below the new leader. Use wood or flexible wire splints, removing them after one growing season.

How to Prune

Current pruning recommendations advise against pruning branches flush to the trunk. Flush cutting is harmful in several ways: it damages bark as pruning tools rub against the trunk, it removes the branch collar, and it goes behind the branch bark ridge. The branch collar is the swollen area of trunk tissue that forms around the base of a branch. The branch bark ridge is a line of rough bark running from the branch-trunk crotch into the trunk bark, less prominent on some trees than on others.
The best pruning cut is made outside the branch collar, at a 45 to 60 degree angle to the branch bark ridge. Leave the branch collar intact to help prevent decay from entering the trunk.
Whenever removing limbs greater than one inch in diameter, use the three-cut method to avoid tearing bark. First, about 12 inches from the trunk, cut halfway through the limb from the underside. Second, about 1 inch past the first cut, cut through the limb from the top side. The limb's weight will cause it to break between the two cuts. Make the third cut outside the branch collar, as described in Publication 430-456.
Don't coat pruning cuts with tree paint or wound dressing, except for control of certain disease-carrying insects. These materials won't prevent decay or promote wound closure. Some tests, however, have shown wound dressings to be beneficial on trees that are susceptible to canker or systemic disease.
Pines and other whorl-branched conifers become denser if new growing tips ("candles") are pinched in half as they expand in the spring. Pinch by hand, as pruning shears will cut the expanding needles and leave them with brown tips. 

When to Prune

Most evergreen pruning is done for corrective reasons, so seasonal timing is not as important as it is for deciduous species. Pruning during dormancy is the most common practice and will result in a vigorous burst of spring growth. Whenever unexpected damage from vandalism or bad weather occurs, prune immediately.
There are, however, certain evergreen pruning activities for specific times of the year. Prune random-branched conifers in early spring when new growth will cover the pruning wounds. "Candles" of whorl-branched conifers must be pinched back in mid to late spring. Maintenance pruning of random-branched conifers is done in summer to keep plants within a desired size range. Remove spent flowers of evergreen magnolias at the end of their blooming season to stimulate new growth and development of a thicker crown. During the Christmas season, minor pruning for decorative purposes usually causes no harm.
Whenever possible, avoid pruning evergreen trees in late summer and early fall. Pruning at this time can stimulate new growth that may not harden off before winter, and thus may be damaged or killed by the cold. (See VCE Publication 430-461, Evergreen Tree Pruning Calendar)

Summer Garden Checklist


Spreading a 2-inch-deep layer of mulch over your soil is one of the best things you can do for your garden. The mulch blankets the ground, shielding the soil from the sun. This keeps it cooler, so your plant roots are happier, and prevents moisture loss from evaporation.
Happily, there's not a single best type of mulch. Anything made from organic matter -- shredded wood, pine straw, a mix of grass clippings and shredded leaves, etc. -- is going to help your soil in the long run as it decomposes and adds to your soil structure.
Learn more about mulch.


Many pesky weeds love summer heat and quickly take the jump from tiny to gigantic. It's important to pull them from your garden, because weeds steal moisture and nutrients from your plants. Many weeds also encourage insect pests and diseases to pop up in your garden.
Weeds are easiest to pull when they're young and small. They also come out of the ground easiest when the soil is moist. Another reason to get them while they're young: You can stop weeds from producing seeds. A single dandelion plant can produce 2,000 seeds in a year. A weed such as lamb's quarters can produce 150,000 seeds in a year. That's a lot of future weeding you can save yourself from doing!
Check out our Weed Identification Guide.

Video: Get weeding tips.

Add Color with Summer Annuals

Once summer heat arrives, many spring-blooming annuals such as pansy, viola, and osteospermum fade. Make your yard look its best by pulling out the spent plants and replacing them with heat-loving varieties such as angelonia, lantana, ageratum, coleus, pentas, portulaca, salvia, sweet potatovine, and zinnia. Heat-loving annuals grow quickly in warm temperatures and will soon provide a beautiful burst of color.
Note: Don't be afraid to renew color in your landscape by replacing summer annuals damaged by drought, pests, or diseases.
Discover top annuals in our Plant Encyclopedia.

Plant Summer-Blooming Bulbs

Summer bulbs such as calla, canna, and dahlia are surefire ways to add color and drama to your landscape all summer long. These varieties are tender, so if you live in a Zone where they're not hardy, plant them after all danger of frost has passed. Once temperatures rise, they grow quickly.
Discover our favorite summer bulbs.

Pinch Mums and Other Late Perennials

Keep mums, sedums, asters, and other fall-blooming perennials standing tall by pinching the top inch or two of new growth. You can do so up to the Fourth of July.
Pinching the tops of the plant typically gives you a more compact, sturdy specimen. It may also give you more blooms from the sideshoots that develop, though the blooms are typically a little smaller and appear a couple of weeks later.
Other perennials that you can pinch in May and June:
  • Balloon flower
  • Bee balm
  • Goldenrod
  • Joe Pye weed
  • Perennial sunflower
  • Phlox
  • Russian sage

Remove Faded Flowers

Remove spent blooms from many of your annuals and perennials, and you might see more flowers! Called deadheading, this process prevents plants from producing seeds so they put more energy into beautiful blooms.
Deadheading cuts back on future efforts, too, for plants that self-seed. Perennials (such as columbine, coneflower, cup plant, false sunflower, garlic chives, and verbena) and annuals (such as datura, flowering tobacco, kiss-me-over-the-garden-gate, larkspur, and spider flower) can self-seed to the point of being weedy in the garden.

Watch for Pests

Like weeding, keeping an eye on pests and diseases in your yard should be done all year. But midsummer seems to be particularly popular for these gardening obstacles.
Some of the more common midsummer problems to watch for include:


If you experience dry summers, or a dry weather pattern, you may wish to water your garden to keep it looking its best.
Most common garden plants prefer an average of 1 inch of water a week. It's best to apply that inch all at once to encourage plant roots to sink down more deeply in the soil.
When watering, apply water directly to the ground rather than getting a plant's foliage wet; water sitting on the leaves can lead to disease. Soaker hoses are great for this!

Raise Your Mower

Raise the height of your lawn-mower blade if you have cool-season grasses such as Kentucky bluegrass, ryegrass, or fescues. More leaf surface keeps the plants healthier during hot, dry weather.

Start a Fall Vegetable Garden

Vegetables fall into two basic categories: Cool-season and warm-season. The warm-season varieties -- tomatoes, eggplants, peppers, cucumbers, summer squash -- are all going now. Once temperatures cool, these plants will fade.
Enjoy continued harvests by planting cool-loving vegetable seeds -- including broccoli, carrots, kohlrabi, lettuce, and spinach -- now so you can enjoy fresh, delicious harvests this autumn.
Learn more about fall vegetable gardening.

Divide Tall Bearded Iris

Most types of iris typically enjoy being divided every three to four years to keep them vigorous and blooming well. The best time to divide them is in summer, when they're dormant.
Learn more about dividing iris.

Add More Color to Your Yard

Keep your yard colorful by adding flowers that bloom in late summer, especially if your garden is starting to feel tired. Many shrub roses are excellent picks for bold color in August, as are new sterile varieties of butterfly bush (such as the Flutterby, Buzz, and Lo and Behold series). 

Harvest Vegetables

Don't let hot weather keep you out of the vegetable garden. Keep up with your harvests to encourage your plants to continue producing and limit pest and disease problems. Insect pests in particular are attracted to overripe vegetables that fall off the plant and begin to rot.
Get tips for harvesting your favorite vegetables.

5 Weed Killers that Won't Harm Plants

Weeds are also called "invasive plants" because they invade your garden and spread. If left unchecked, a weed infestation can take over an entire yard and turn it into an eyesore.
Many people have trouble dealing with aggressive weeds because the poisons and weed killers that work on the weeds also harm your regular garden plants.
The following are all options you can exercise that will target weeds specifically and leave your other plants safe and sound.

1. Cornmeal

This method is useful if your yard or garden is new and not already established.
Wait for your plants and seeds to start growing, and then treat your lawn to prevent weeds from appearing. Using your hands, broadcast a thin layer of cornmeal over garden and landscaping areas. The cornmeal prevents seed growth, in this case you're aiming to stop weeds from seeding, so this is why you want to wait before spreading it on the ground. Doing it sooner will stunt the good seeds for your plants. Cornmeal will also attract worms that naturally churn and enrich the soil, so cornmeal is a good idea even if you don’t have a big weed problem.

2. Vinegar

You probably have a weed killer in your home right this very minute. If not, you can buy one at any grocery store: vinegar.
Get undiluted white vinegar and pour it into a spray bottle. Spray the vinegar directly on the weeds you wish to eliminate, and you'll notice results within hours. Unlike many chemically-created weed killing agents, vinegar is a natural and perfectly safe substance for you, your children, and your pets. Vinegar can be safely ingested (though the taste is rather unpleasant), and it can be touched with bare skin. Vinegar is also affordable when compared with formulated chemical killers.
For best results, spray vinegar during a sunny day with minimal wind. The wind can carry vinegar away from weeds, and that’s not what you want. Vinegar can have adverse effects on other plants, but if you spray weeds directly it will not harm your other greenery or the soil itself.
  • Vinegar is also an effective way to control garden bugs and pests. Spray it in areas where you’ve seen ants, slugs, or stray cats. The smell will keep them away.

3. Baking Soda

You don't have vinegar on hand? What about baking soda? This is another safe product that can be used for weed control. Spread baking soda directly on weed-ridden areas to make the soil less hospitable to weeds. Baking soda can easily be sprinkled into cracks and crevices where weeds appear, such as sidewalks and driveways.

4. Salt Water

You can also boil two cups of water on the stove and add one cup of salt. Be sure to handle the boiling water carefully as you pour it directly onto weeds.
  • Plain salt can also be used without the water, but you want to exercise caution with this. “Salting the fields” is known for making the soil inhospitable to plant life of all kinds, so you want to be judicious.

5. Mulch

Spread mulch in garden and landscaped areas to smother weed growth. If you notice weeds appearing in these areas anyway, cover the area with newspaper. The newspaper will prevent light and air from getting to the soil, and that will kill weeds.
  • Don’t cover the plants you want to save.


The best natural way to prevent weeds is to maintain a healthy lawn. Thick, lush grass offers little bare soil that weeds can latch onto. Keep your lawn looking good, and you’ll see a lot fewer weeds.
Eliminate weeds safely by treating them directly and keeping your soil healthy. If you treat the weeds directly, you can get rid of the ones you don't want and save all the others.

20 Colorful Plants For Shade Gardens

Plant some of these beauties for great garden color, even in shade

61 Cool Container Gardens

Beautiful container plantings for your deck, entryway, or yard