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    Save the Date: Perennial Plant Society’s 30th Plant Sale is April 4, 2020, 9 a.m. – 1 p.m. at the new Expo 3 Building at The Fairgrounds Nashville. Here’s where you can find the newest varieties of perennials, shrubs, vines and annuals from local growers, along with long-time, never-fail favorites, ready for spring planting. Learn more at the PPS website.

     

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Fall leaves = free mulch

Question: We have several maple trees that blanket the lawn with leaves in the fall. Can we rake these off the lawn into the garden beds to use as mulch?

 

fall-leavesFall leaves are a good source of mulch for garden beds. As they decompose, they improve the soil structure and return nutrients to the soil, and as mulch, they help retain moisture in the garden beds and slow the growth of winter annual weeds that may pop up.

You could just rake them or blow them off the lawn directly into the beds, but it’s better to shred them before you pile them on top of the perennials and around trees and shrubs. Leaves that have been chopped up will decompose faster. A thick layer of unshredded leaves may also become matted and smother plants underneath, and may prevent water from reaching the soil. You can chop the leaves by mowing over them and collecting them in a bagging attachment, or by using a leaf shredder.

Here are guidelines for using leaves as mulch are from the UT/TSU Extension office:

*Use a 3- to 4-inch layer of shredded leaves around trees and shrubs in annual and perennial flower beds.

*Mix leaves into kitchen garden beds and in beds where you plant annual flowers. Most of the leaves will decompose before planting time next spring. A bonus: if you have heavy clay soil, a thick layer of leaves tilled into the soil will improve the soil structure.

*Be aware that oak leaves may change the pH of the soil over time, making it more acidic, so you may have to apply lime to maintain a favorable number. If your beds are mulched primarily with oak leaves, you should have the soil tested about every three years. Oak leaves are also tougher and decompose more slowly, so it’s especially important to chop them before you use them to cover your perennial beds.

Leaves can also be added to compost as one of the carbon-rich “brown” ingredients. If, after you’ve chopped and used as much of your bounty of leaves as possible on the garden beds, save the rest to use later in the compost, or for mulch again next spring. Bag the leaves and keep them dry so they don’t decompose by the time you need them again in a few months.

June garden tips & tasks

June is the garden’s high season, “the time of perfect young summer,” said gardener designer Gertrude Jekyll. Here are some garden tasks to enjoy during this “perfect” time.

Early in June

Tomatoes do best with consistent moisture as they begin to ripen.

Tomatoes do best with consistent moisture as they begin to ripen.

Summer tomatoes will begin ripening soon. Make sure they receive consistent moisture. Use mulch around the plants to keep them from drying out quickly. Replenish mulch around in all garden beds to help keep plants’ roots moist as the weather heats up. Continue reading

Coffee grounds as mulch? Don’t do it!

I get coffee grounds from my local coffee shop. Can I use them directly on the soil as mulch (without mixing anything into it except to rake it into the soil)? The grounds are wet when I get them from the coffee shop. Should I let them dry out a little before putting it on the soil?

coffee groundsIn just about every listing of “ingredients” for a successful compost pile, you’ll find coffee grounds among the nitrogen-rich kitchen waste “green” ingredients that make up the mix. But it’s a mistake to use coffee grounds alone. They are very acidic, and over time will change the pH of the soil – the measure of its acidity or alkalinity – to the point that plants that prefer alkaline soil will suffer. Continue reading

May garden tips & tasks

May is a busy and beautiful time in the garden. Here are tasks and tips to keep you busy this month.

Early in the month

If you haven’t already gotten those warm-season vegetables in the ground, plant them now! Tomatoes, peppers, squash, okra, beans, eggplant and other favorites will get off to a fast start now that the weather is warm.

zinnias-1

Set out bedding plants of zinnias and other summer annuals.

Set out bedding plants of zinnias, celosia, snapdragon, begonias, petunias, coleus – all the favorite summer annuals.

Plant plenty of basil in a sunny location to use in summer recipes. Clip and use it frequently, which allows the plants to grow sturdier. Snip off flowers as they begin to form. Continue reading

Winterize your roses

I’ve heard gardeners talk about “winterizing” roses. What does that mean? And how do you do that?

Rose

Winterize rose shrubs to prevent damage from cold and wind.

If you live in an area that experiences intense cold or cycles of freezing and thawing, you may have heard about the importance of winterizing your roses. While rose shrubs are generally hardy, some varieties may be vulnerable to extended cold weather and strong winter winds. “Winterizing” helps protect roses from winter damage.

The process begins in late summer. You should discontinue fertilizer applications about mid-August, to slow down new growth. Stop cutting off the dead blooms in early October, which signals the plant to stop producing new growth.

Now comes the important “winterizing” part: Between now (late November) and mid-December, cut the canes back to 2 to 3 feet tall to keep them from blowing around in the winter winds, loosening the soil around the roots. Rose experts at the Nashville Rose Society suggests placing a 12-inch high mound of soil or mulch around each bush. To minimize winter damage at the end of each cane, you can also erect a small cage of chicken wire around each bush and pile about two feet of hay or other loose organic material inside.

Miniature roses and others grown in containers can be moved to an unheated garage or other space where the temperature remains above 20 degrees. Plants should be watered just enough to keep them moist.

For advice on roses in Middle Tennessee (where The Garden Bench calls home), I usually turn to the rosarians at the Nashville Rose Society, who provide excellent information on growing roses at their website. We are in USDA Hardiness Zone 7a, and the schedule reflects normal conditions in our climate. Gardeners in colder areas may adjust accordingly.

Rose enthusiasts can also get information (and see photos of beautiful blooms) from Birmingham, Alabama-based rose expert Chris VanCleave aka “The Redneck Rosarian.” He writes about roses, hosts podcasts, and keeps the conversation going with #RoseChat on Twitter.

July garden tips & tasks

Summer is in full swing. Here’s how to enjoy the garden and it’s July bounty:

Early in the month

Geraniums

Cut geraniums and other summer annuals to encourage them to grow fuller.

In the kitchen garden, pick zucchini, summer squash and cucumbers while they are still small and tender.

Plant a second crop of those summer vegetables that grow quickly: bush beans, squash and cucumbers are easy favorites.

Watch for Japanese beetles. Experts don’t recommend Japanese beetle traps, which may attract more beetles to your landscape than would normally visit. Pluck them off the plants and drop them into a pan of soapy water.

If summer annuals such as coleus or geraniums are getting leggy, cut them back to encourage them to grow bushier. As a bonus, root the cuttings in water to have even more plants.

Before you leave for vacation, arrange for someone to water annual, vegetable and perennial beds and container gardens while you’re away. Make it easy for them: set up sprinklers in strategic places and hire a neighborhood youngster to turn on the faucet if it doesn’t rain.

Mid-July

Zinnias

Cut zinnias often. The more you cut, the more they bloom.

Bearded irises can be divided every three to five to years; mid-July is a good time to do it.

Lawn growth may slow down in the heat, but you may still have to mow. When you do, only cut about a third of the lawn’s height.

Cut chrysanthemums back in order to delay flowering until fall.

Herbs, annuals and perennials growing in containers need water every day when it’s hot. Don’t let them droop.

Keep cutting summer flowers such as zinnias and cosmos often; the more you cut, the better they bloom.

Later in the month

Tomatoes

Keep the soil evenly moist for tomatoes.

It’s hot, so get out early in the day to work in the garden. Drink plenty of water, wear a hat and use sunscreen.

Keep the soil around tomato plants evenly moist. Inconsistent watering can cause tomatoes to develop cracks.

Some summer flowers that grow tall may need staking to keep them from toppling in a heavy rainfall.

Continue to deadhead plants – cut off the spent flowers – to extend the blooming period.

Don’t forget about shrubs and trees planted this spring; they need an extra dose of attention in this heat. Give them a slow drink from a dripping water hose once or twice a week. A layer of mulch around newly planted threes and shrubs helps keep the soil moist longer.

Check the mulch in perennial and annual beds. Add more if it’s beginning to look thin. A good layer of mulch will help keep soil moist longer in the summer heat.

Enjoying a bit of Tranquility: Franklin’s Cornelia Holland nurtures the shade garden

Cornelia Holland, Photo courtesy University of Tennessee Institute of Agriculture.

Cornelia Holland, Photo courtesy University of Tennessee Institute of Agriculture.

she calls Tranquility at her home. She has donated plants to the University of Tennessee Institute of Agriculture in Knoxville to establish Tranquility – The Cornelia B. Holland Hosta Grden at the University of Tennessee Gardens. Read the story in Saturday’s Tennessean.

 

May garden tips & tasks

May is a busy and beautiful time in the garden. Here are tasks and tips to keep you busy this month.

Week 1

Azalea The Garden Bench

Prune azaleas shortly after they bloom.

Plant your summer kitchen garden with warm-season vegetables: tomatoes, peppers, squash, okra, beans. Water newly planted garden beds well, and keep them moist as seeds sprout.

Foliage left from spring-flowering bulbs – daffodils, tulips and so forth – can be cut down if it has turned brown.

If you need to prune azaleas, do it now; don’t wait any longer, or you risk cutting off next year’s flowers, which will begin to form soon.

Set out bedding plants of favorite summer annuals: petunias, begonias, annual salvia, cleome, cosmos, celosia, snapdragon, zinnia.

Find a comfortable spot for houseplants that will spend summer outdoors, protected from too-harsh sun and strong wind and rain.

Week 2

Hellebores The Garden Bench

Dig and divide hellebores

Use mulch in perennial and annual beds and borders to keep weeds in check, and to retain moisture in the soil.

A cluster of aphids on tender new growth of plants can be washed away with a strong spray of water from the hose.

Container gardens dry out quickly in hot weather, so if your “garden” is a collection of pots on the deck or balcony, they need to be watered frequently.

Divide hellebores. Dig up as much of the root ball as possible and gently separate the roots. Replant right away, or share with friends (reminding them to plant as soon as possible).

When you mow, set the mower to cut high, removing only about a third of the height of the grass to keep it healthy. Don’t shear the lawn.

Week 3

Cut flowers The Garden Bench

Cut spring flowers to enjoy indoors.

There will always be unwanted plants (sometimes known as weeds). Pull or dig them out of garden beds when they are small, but especially before they form seeds. Weeds are easier to root out after watering or after a rain, when the soil is moist. Annual weeds that haven’t gone to seed can be tossed into the compost.

As summer approaches, make sure spring-planted trees and shrubs continue to get enough moisture. Provide about an inch of water a week — by hose or sprinkler if it doesn’t rain.

Enjoy the late spring bounty of flowers indoors. To help them last longer, cut flowers and foliage early in the morning and place them in water right away.

Grass clippings make good mulch, but allow them to decay before you use them on beds and borders.

Watch for spider mites on roses and other shrubs if the weather turns hot and dry. A strong spray of water on the undersides of leaves every few days can keep them under control.

Week 4

Thyme The Garden Bench

Thyme and other herbs are at their peak just before they bloom.

Many herbs are at their peak just before they bloom. Harvest them to use fresh, or preserve them by drying or freezing to use later.

As perennials flower and fade, cut the dying blooms. This will encourage the plant to bloom longer.

Divide irises after they finish blooming. Cut the leaves to about five inches, then lift the tubers with a spading fork. Separate the rhizomes and cut off damaged portions, then replant the rhizomes close to the soil surface.

Hummingbirds are welcome summer guests in the garden, visiting flowers and nectar feeders. If you provide feeders, change the nectar every day or two and clean the feeder thoroughly. Standard nectar recipe: 1 part sugar to 4 parts water; boil for five minutes, and allow it to cool before filling the feeder. No red food coloring needed.

Continue to care for new shrubs in winter

We planted aucubas and hollies in the spring and kept them watered all summer, and they’re doing well. Do we need to water them in winter, too?

Aucuba japonica

Replenish mulch at the base of spring-planted aucuba and other shrubs.

Spring-planted shrubs that received regular water should be well-established by fall, so you can cut back on the amount of water they receive. But don’t neglect them completely. It’s a good idea to replenish the mulch, adding enough so that it’s about three inches thick. Mulch holds moisture in the soil, and also keeps it from freezing and thawing as temperatures swing from cold to warmer and back again. Remove any dead or diseased leaves from under the shrubs before you add mulch, and remember not to pile mulch up against the trunk.

One other winter grooming tip: If you have deciduous trees in the area that have dropped leaves onto the shrubs, take time to remove the leaves, especially if there are so many that they would block the sun.

As I mentioned in last week’s question-and-answer, a yard-full of leaves is a good source of mulch for those shrubs. Chop them with the mower before you spread them on the ground under the shrubs.

Pamper those strawberry plants

I have strawberries that did well in the spring but seems to have suffered a bit over the summer. What’s the best way to prepare the bed for winter? It is okay to use mulch on strawberry plants?
Strawberry plantsStrawberry plants have shallow roots, so it’s possible that they suffered from drought if you didn’t water regularly. They also need to be mulched, which can help suppress the growth of weeds. Pine straw is a good mulch to use in a strawberry bed, because it can cover the soil without smothering the crowns of the plants.

Here’s advice on strawberries from garden expert Barbara Pleasant, from her book The Southern Garden Advisor:

Pull weeds from the strawberry bed in September, then feed the strawberries with a high-nitrogen fertilizer. This should be the heaviest fertilization because strawberries produce latent buds, which become next year’s fruit, Pleasant explains. Water the bed well.

Mulch the bed in November. Pinch off leaves that are discolored and pull up any weeds that may have popped up.

Fertilize again in February, with a lighter dose this time, and prepare to enjoy the berries in April and May.

By the way, Pleasant says she prefers the spring-bearing varieties over those that are everbearing, which don’t produce as well. She recommends four varieties: ‘Earliglow,’ ‘Apollo,’ ‘Cardinal’ and ‘Surecrop.’

October in the garden is anything but dull. Metro Parks offers ways to keep your garden mind entertained. Head Outdoors for Fall  (plus Garden Tips, Tasks & Events) in the October Garden Calendar in Saturday’s Tennessean and at Tennessean.com.

Tomato troubles: Blossom end rot

What can I do to keep tomatoes from forming a black spot on the bottom? They look beautiful, then you turn them over and see it. Are the tomatoes safe to eat if you cut the spot out?

 

Tomatoes

Young tomatoes may be susceptible to blossom end rot.

The black spot on the bottoms of tomatoes is a condition called blossom end rot. Rodale’s Vegetable Garden Problem Solver provides a concise explanation:

Blossom end rot is usually caused by water stress due to lack of moisture, which hampers the plant’s ability to take up enough calcium from the soil. But it can also be caused by too much water, soil pH that is too acidic or too alkaline, too much nitrogen fertilizer, or other problems. The area first turns tan and leathery, and then other pathogens can invade and cause the rot (it turns black and soft).

Rodale suggests removing any tomatoes that show signs of rot so the plant can put energy into developing new, healthy tomatoes. If the soil is dry, water it well and use mulch to conserve moisture. Throughout the season, keep the soil evenly moist by watering as needed.

At the end of the season, be sure to clean up any fruit that falls to the ground, as it may contain secondary rot organisms. And next year, prepare the bed to encourage the plants to develop good root systems – plant in loose, fertile soil, and check the soil pH to see that it measures above 6.5. Add lime as recommended to raise the pH to 6.5 to 6.8, Rodale suggests.

The experts at Rodale suggest to compost the immature fruit that is beginning to show signs of blossom end rot, because they probably won’t ripen properly anyway, but it also looks like it doesn’t hurt to cut off the spot and use the tomatoes if they’re at a stage that you want to do that. In my experience, once they start to rot, they go quickly, though.

By the way, blossom end rot can also affect peppers, eggplant, squash and melons.

July in the garden: What to do with that bounty of herbs? See the July Garden Calendar at Tennessean.com for herbs information, plus this month’s events, tips and tasks.