April Garden Tips & Tasks

Spring — however capricious it may be — has arrived, and it’s time to head back outdoors, keeping an eye on the weather. Gardeners in Middle Tennessee — Zone 7a, where The Garden Bench calls home — are anxious to get the season started. Warmer areas are already in full swing; if it’s cooler where you are, it’s getting close!

If you live in Middle Tennessee, there are a couple of good garden events to look forward to — both live this year! The annual Perennial Plant Sale sponsored by the Perennial Plant Society of Middle Tennessee will be held Saturday, April 9, 2022. The Herb Society of Nashville’s annual Herb Sale will be Saturday, April 30, 2022. Both will be at The Fairgrounds Nashville’s Expo 3 Building. Details are in the sidebar, or visit the organizations’ web sites. The annual Herb & Craft Fair sponsored by First Unitarian Universalist Church of Nashville will be Saturday, April 23, 2022, 9 a.m. – 3 p.m.

Here’s what else is on your garden to-do list for April.

Early this month

Did your hardy herbs survive winter? Trim dead foliage of sage, rosemary, thyme, oregano and other cold-damaged herbs. Replant those that didn’t make it through the freezing weather.

Trees and shrubs planted in spring need plenty of water during the first year of growth, especially as the weather gets warmer.

Set out hummingbird feeders to welcome the birds back to your garden. Hummingbird nectar recipe: one part sugar to four parts water. It’s not necessary to use red food coloring.

Plant your favorite herbs: parsley, sage, thyme, rosemary can be planted early in the month. Basil and dill are more tender herbs, so wait a bit longer to be sure the weather is warm enough.

To have a big display of flowers in summer, sow seeds and plant summer-flowering bulbs in April: zinnias, sunflowers, cleome, cosmos and other summertime favorites.

Mid-April

Get rid of weeds while they’re small and easy to pull. Use mulch to keep weed growth (and weed-pulling) to a minimum.

Mid-April marks the official last-frost date in Middle Tennessee, and it’s usually safe to set out warm-weather bedding plants such as petunias, coleus and begonias, and vegetable transplants — tomatoes, peppers, eggplants. But keep an eye on the weather. Spring is unpredictable!

Sow seeds of okra, cucumbers, squash, beans, melons, and other kitchen-garden favorites.

Don’t skimp on mulch. Use it to keep weed growth (and weed-pulling) to a minimum, and to help keep the soil moist in annual, perennial and vegetable beds.

Remove the dead flowers and stalks of daffodils, tulips and hyacinths, but leave the foliage until it turns yellow. This is the time spring-flowering bulbs build up energy to bloom again next year.

Later this month

If you don’t have space for a kitchen garden, at least plant herbs in a pot. Some favorite container combinations for cooks: parsley, basil and thyme; rosemary sage and chives; mint, basil and dill. Remember to water containers frequently as summer weather approaches.

The best time to prune azaleas, flowering quince, forsythia, lilac and other early-flowering shrubs is right after they finish blooming. These plants begin forming buds for next year’s flowers on this year’s growth.

Many houseplants thrive in shady, protected spots outdoors. Place them where they won’t get blown by strong winds, pelted by hard rain or disturbed by marauding animals.

If you plant shrubs and trees this spring, make sure they get plenty of water during their first year of growth, especially as the weather gets warmer.

Provide about an inch of water a week to lawns and garden beds.

Kids learn the joy of gardening

Want to share the joy of gardening with the children in your life? Take a look at these strategies from gardening experts that make time in the garden interesting and fun.

Photo courtesy Nashville Lawn & Garden Show

Each year, the Nashville Lawn & Garden Show brings thousands of visitors to the Fairgrounds Nashville for an early taste of Spring. This year (March 2 – 5, 2017), the theme is “Gardening For the Future,” and the lecture schedule is heavy on ways to make gardening fun and meaningful for future gardeners – our kids. I asked some of the lecturers to share their ideas.

“Most kids love to get their fingers in the dirt and to dig holes,” gardening or not,” says Todd Breyer, who is one of the show organizers. “They are naturally drawn and fascinated by unusual shapes, flower colors, insects, birds and butterflies in the garden.”

April garden tips & tasks

Here in Middle Tennessee (Zone 7a, where The Garden Bench calls home), April brings the garden into sharp focus. Where to begin? Here’s a list of suggestions, week by week, of tips and tasks for April in the garden.

Week 1

Flowering quince

Prune forsythia and flowering quince soon after they finish blooming. Prune out about one-third of the branches by cutting out the oldest limbs as close to the ground as possible. Mulch around the shrubs to discourage weeds and to retain moisture.

It’s still too early to set out most vegetable transplants, but not too early to prepare the beds. Till the soil and work in organic matter. Cover with mulch until you are ready to plant.

Begin fertilizing roses after new foliage appears.

Keep your mower blade sharp, and when you mow, don’t cut too short. Set the mower so that it removes only about a third of the height of the grass.

The hummingbirds will arrive soon. Prepare a solution of one part sugar to four parts boiling water. Let it cool, then fill the hummingbird feeders. Red food coloring is not necessary.

Week 2

Average last frost date in Middle Tennessee is around mid-April. But don’t be fooled by fickle weather. It may still be too cool for some heat-loving plants, such as basil.

Easter lily

Begin planting ornamental grasses and perennials. Make sure they get regular water after planting.

Peonies tend to flop over in heavy rains, so go ahead and place supports around the shoots now. The growing foliage will cover the supports, and the plants will stay upright in the rain.

After spring-flowering bulbs finish flowering, allow the leaves to remain until they can be pulled easily from the ground. This allows time for them to store food for next year’s growth.

Plant your Easter lily in a sunny spot after the flowers fade. Do not place it in the same bed as other lilies, as it can transmit a disease to other plants.

Week 3

Begin setting out bedding plants. Water plants thoroughly about 12 hours before you plant them. Dig individual holes and place plants at the same depth they grew in their pots. For best performance, break apart and spread tightly wound masses of roots as you plant, and snip off old blossoms. Replace the soil around the roots and water the plants well. Mulch planting beds about in inch deep.

Parsley

Plant your herb garden: rosemary, thyme, mint, lavender, oregano, parsley and other herbs can go in the garden now. Just to be on the safe side, save tender basil to plant later in the month.

Set out marigolds, cosmos, petunias, begonias and other annual flowers. Plant coleus for color in shady spots, in containers or in the ground.

Sow vegetable seeds and keep them watered, but not soggy, until they germinate. The general rule is about an inch of water a week. Get out the rain gauge!

Set out tomato transplants. Set them deeply in the soil so that only the top few leaves are showing. Plant basil, or set out basil transplants.

Week 4

Newly planted shrubs need regular, thorough watering to help establish their root systems. Soaker hoses are an efficient way to water.

Geraniums

Plant geraniums in containers or in the ground. They prefer morning sun and afternoon shade.

Pluck young weeds out of the garden as soon as they emerge. It’s easier to keep them out if you get them while they’re small.

If you MUST prune azaleas, do it shortly after they finish blooming. They bloom on the previous year’s growth, so to prune later risks cutting off next years flowers.

Don’t forget about your houseplants. As the weather gets warmer, they need water more frequently. If you have houseplants that spend the summer outdoors, place them in a shady, protected area.

Get out and meet other gardeners this month! Check out the calendar Events calendar at left, and in my newspaper column at Tennessean.com.

 

Dreaming of warmer weather: a to-do list

Here’s a ray of sunshine to warm up a winter day…

It’s hard to think about a garden when the ground is frozen solid. But for gardeners, January is not a total loss. I looked around the world of garden calendars to find to-do lists to back up that claim, and came across these nice little bits from The Garden Girls — Dr. Sue Hamilton and Beth Babbitt – at the University of Tennessee Plant Sciences Department. Here’s some of what they suggest for January, when it’s too cold to get out and dig:

• Use the time to design and plan. Now that the garden in bare, take a look at  the “bones” and determine where you may need to move plants, add new plants, add hardscape, or make new beds.  If it looks a little dull out there right now, consider adding plants that can provide winter color and interest. Take notes so you can remember these ideas when the time comes for action.
• Gather your seed-starting supplies if you want to get a head start on spring by starting seeds indoors. The early-season plants should be started indoors by the end of the month. Go ahead and place your orders from mail-order services to get the best selection of plants and seeds.
• Give your houseplants a little love. Trim, groom, clean, divide and re-pot as      needed. Still hanging on to that Christmas poinsettia? Take the pot out of the foil wrap and place them in another container to catch overflow water. Keep it in bright sunlight and the soil evenly moist. When the color starts to fade, cut it back to about half and continue to treat it like a houseplant. After the danger of frost, move it outdoors where its lovely green foliage will grow all summer.

The Garden Girls also have advice on how to protect landscape plants during a deep freeze:

• When the temperatures are below freezing, avoid contact with trees and shrubs because frozen plants can break easily. Ice-laden plants are especially prone to breakage. Lightly cover plants that are subject to winter damage, but avoid using plastic, which can heat up too much when the sun is out. Don’t walk on frozen grass.
• If you do find winter damage, don’t be in a rush to prune. Remove broken limbs, but if it’s simply burned foliage you see, wait to see if the damage is superficial; it may bounce back.

Think of January as a time of anticipation. Spring will be here before you know it.

Hydrangeas’ color codes

My hydrangeas have pink flowers. Is it true I can make them change to blue? How do you do that? Can I also change my white hydrangeas to pink or blue?

The French hydrangea (Hydrangea macrophylla) is the one with the big, round, blue or pink clusters of flowers. The color of the flowers depends on the pH level of the soil – how acid or alkaline it is. French hydrangeas growing in alkaline soil have pink flowers; if the flowers are blue, that indicates that the soil is acid.

There’s a lot of science surrounding the explanation of soil’s pH that involves discussion of hydrogen ions in the soil – way beyond the scope of this column. One simple thing to remember is that pH is measured on a scale from 0 to 14; pH 7 is neutral, below 7 is acid, above 7 is alkaline. You can learn your soil’s pH level by having the soil tested at your county’s extension service.

You can change the soil’s pH level (and therefore, the color of the French hydrangea flowers) by adding lime to the soil, to make it more alkaline (pink). Add aluminum sulfate, to make it more acidic (blue). How much of either amendment to use depends on the soil type and current soil pH – a good reason to have the soil tested before you proceed.

The change doesn’t take place right away. Changing the pH of the soil this year will mean changing the color of next year’s blooms.

Soil pH doesn’t affect the color of white hydrangeas such as Annabelle or oakleaf. Their flowers are always white, though as they age, Annabelle flowers take on a green tint.  Oakleaf hydrangea flowers mellow to a rosy pink shade

Garden events in Middle Tennessee

May 18: Gardening with chickens with Megan Lightell, 10 a.m., Gardens of Babylon (at the Farmer’s Market) Click here to sign up.

May 21: Perennial Plant Society of Middle Tennessee meets at Cheekwood’s Botanic Hall. Speaker is Jimmy Williams from Paris, Tenn, on “The Perennial Border from February through December.” Refreshments at 6:30, meeting at 7 p.m.
May 23: Middle Tennessee Hosta Society meets at Cheekwood’s Potter Room, 7 p.m. Featured speaker is Jason Rives, owner of Petals From the Past in Jemison. Ala.; topic is “Incorporating Antique Roses into the Hosta garden.”

Grow herbs in containers

QUESTION: I want to grow herbs for cooking, but we don’t have space in the yard. Can herbs do okay growing in pots?

Grow three types of basil for an attractive container combination.

Many herbs can grow very well in containers, and if your “garden” space is a deck or a condominium balcony, it’s the best way to have fresh herbs at your doorstep. The things you need to guarantee success are good growing medium, ample sunlight, and plenty of water. You can sow seeds, but transplants get the garden off to a faster start.
Begin with the soil – and by that I don’t mean the dirt you dig up in the yard, but a soilless potting mix, which is lighter and less likely to become compacted in the container. Members of the Herb Society of Nashville recommend a mix that is heavy with peat. Slow-acting organic fertilizer can also be added.
After you fill the pot with growing medium and the herb transplants of your choice (more on that in a minute), find a spot on the deck or balcony that gets several hours of sunlight – at least four to six — a day. After it’s planted, the challenge of keeping a garden pot growing is making sure it gets enough water. At mid-summer, when days are hot and dry, pots dry out quickly and often need to be watered every day.
The container itself is up to you; almost anything that will hold potting mix and drain well can be used as a planter for herbs. In fact, a variety of types of containers may make an interesting arrangement. Consider baskets, bowls, an old wheelbarrow – anything that holds a moderate amount of soil and a few plants (drill holes in a container that doesn’t drain naturally). Of course, traditional pots are fine, too.

Mint is a good choice for a container herb garden.

As for what to grow: Basil, chives, dill, mint, oregano, parsley (curled and Italian), sage and thyme all can grow well in containers. Cilantro also does well, but you should remember that it is a cool-season herb that goes to seed quickly when the weather turns hot. Grow them in individual pots, or consider some container combinations: rosemary sage and chives; parsley, basil and thyme; mint, basil and dill are all good choices for container herb gardens.

Sparking interest in Fireflash

QUESTION: I have a new houseplant known as a Fireflash. How should I take care of it?

Fireflash. Photo by Maja Dumat – flickr.com

Fireflash (Chlorophytum orchidastrum is the botanical name) is a houseplant that you don’t see often, but sounds like it would be a nice addition to any indoor garden. It’s a striking plant, with large, green pointed-oval leaves and bright orange stems. The Flowers & Plants Association, based in the UK, describes it as “a very easy plant.”
Fireflash is related to the more familiar spider plant (Chlorophytum comosum) and enjoys similar growing conditions: it’s tolerant of a range of light conditions (but will probably do better in low light than spider plant) and normal room temperatures. Water Fireflash sparingly about once a week during warm weather, less in winter; don’t allow the soil to dry out completely, but don’t let the plant sit in water, either. The Flowers & Plants Association suggests feeding it every two weeks during the growing season and not at all during winter.

When daffodils don’t bloom

QUESTION: I have a lot of daffodils that shoot up nice and green, but some varieties don’t bloom as well as they once did. What do they need? Some of these have not been in the ground very long.

We’re coming into prime-time for daffodils. The early varieties have bloomed and sailed gracefully through Middle Tennessee’s March cold snap. Of course you’d like to continue to enjoy as many blooms as you can.

The web site of the American Daffodil Society has a long list of reason daffodils may not bloom. See if any of these conditions may affect your flowers:

Too much shade: Daffodils should be planted in an area that gets at least a half-day of full sun, or more, if they are planted in partial sun.

Crowded conditions: After bulbs have been growing in the same place for many years, they may need to be dug up and divided. They divide themselves every year or two, and the clumps of bulbs compete for food and space. They respond by ceasing to bloom. After the foliage turns yellow later this spring, dig the bulbs, separate them, and replant them about 6 inches apart, 6 inches deep.

Fighting for food: Bulbs that are planted under evergreen trees or with other fast-growing plants may be competing against those plants for the available nutrients in the soil – and losing. The result would be weak plants and no flowers.

Impatient gardener: If you were too quick to cut down the foliage the previous year, the bulbs may not have had time to replenish themselves enough to flower. The ADS explains that daffodils replenish their bulb for about six weeks after they bloom, and the leaves should not be cut off or tied up (which blocks the sun) until they turn yellow.

In general, daffodils need well-drained, slightly acidic soil in a sunny location, and plenty of water while they are growing. They benefit from a top-dressing of 0-10-10 or 0-0-50 fertilizer, but avoid high nitrogen fertilizer, which promotes foliage growth at the expense of blooms. The right growing conditions result in a beautiful, daffodil-filled spring.

Jade plant rejuvenation

QUESTION: I have a jade plant that has grown well for several years, but the stems are tall and bare and all the leaves are at the top. I admit there are times I forget to water it. Can this be fixed?

Given the right conditions, a jade plant (Crassula ovate) should be an easy-care houseplant. It’s shiny, fleshy leaves make it an interesting addition to your décor. If it has been neglected, it can probably be rejuvenated as long as there is still healthy growth.

You can take stem cuttings of the old plant and root them in new soil. Houseplant expert Barbara Pleasant suggests this method: Cut the stems just below a node, and allow the cuttings to dry for about five days, then plant them in a mixture of damp sand and peat moss. Keep the soil moist, but not soggy. Each cutting should grow roots and form a new plant. You may also have some success if you root the cutting in water, and plant the rooted cutting in potting mix.

That doesn’t address the problem of neglect, though. Jade plants can be forgiving, yes, but they do need a little attention.  The plants become leggy when they receive too little light. They need about four hours of filtered sun each day, and average room temperature. Allow the soil to dry slightly between waterings. Spring through fall, feed every few weeks with a balanced houseplant fertilizer at half the normal strength, Barbara Pleasant suggests. It is not necessary to fertilize in winter. A jade plant may enjoy the summer outdoors as long as you can provide a shady, protected spot.

Give mums a trim now … or later

Question: In your opinion should chrysanthemums be cut back in the late fall or spring?

Different sources say different things about what to do with mums after they are browned by frost. One source advises to cut them back in the spring; another says to cut them back to about 8 inches after they finish blooming in the fall.

In my experience, either way seems to work. I usually leave them until spring in my garden beds, which tend to be informal (some might call them “messy”), and often the new leaves start to come up from the roots very early — as early as February, if we have a mild winter. At that time, I cut back all the dead stems and divide and move clumps where necessary, and they grow happily and vigorously through the spring and summer. I cut them back a couple of times during the summer to delay flowering, and they start to bloom in the fall.

If you prefer a tidier look throughout the winter, cut off the blooms after they turn brown. They will rest during winter and be ready to pop up again early next spring.