Gardening Guides
How to Maintain Your Garden to Ensure Its Long-Term Health
Experts weigh in on how to keep your plants thriving and your garden looking good for years to come
Established gardens that have been growing for three years or more require different care than newly planted landscapes. Lawns may need to be reseeded, trees could require pruning and nutrients might need to be added back to the soil. We asked three landscape experts on Houzz — Donald Pell, Mariane Wheatley-Miller and June Scott — to share their advice on caring for lawns, trees, hedges and other plants over the long term, as well as how to edit gardens as they grow and change. (Hint: It’s OK to transplant, hard-prune and replace some plants.)
Landscape architect June Scott of June Scott Design in Pasadena, California, suggests that those who have had gardens for a few seasons consider the following: How have the plants grown in? Do they appear crowded? Are there bare spots?
“In a garden’s youth, some unevenness in the way plants are filling in is to be expected. But once a garden is mature, it pays to take a good look and see which plants need trimming or removing, and what areas might benefit from additional plants,” she says. Some short-lived perennials, such as lavender, may need replacing after a few years.
“In a garden’s youth, some unevenness in the way plants are filling in is to be expected. But once a garden is mature, it pays to take a good look and see which plants need trimming or removing, and what areas might benefit from additional plants,” she says. Some short-lived perennials, such as lavender, may need replacing after a few years.
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Landscape architect June Scott of June Scott Design in Pasadena, California, suggests that those who have had gardens for a few seasons consider the following: How have the plants grown in? Do they appear crowded? Are there bare spots?
“In a garden’s youth, some unevenness in the way plants are filling in is to be expected. But once a garden is mature, it pays to take a good look and see which plants need trimming or removing, and what areas might benefit from additional plants,” she says. Some short-lived perennials, such as lavender, may need replacing after a few years.
“In a garden’s youth, some unevenness in the way plants are filling in is to be expected. But once a garden is mature, it pays to take a good look and see which plants need trimming or removing, and what areas might benefit from additional plants,” she says. Some short-lived perennials, such as lavender, may need replacing after a few years.
Transplant or replace plants if needed. Landscape architect Mariane Wheatley-Miller of A.J. Miller Landscape Architecture in Syracuse, New York, advises clients to consider transplanting or replacing plants that have been damaged, have grown too crowded or aren’t earning their keep.
“Check to see if all the seasons are covered for interest,” she says. “Plantings should be diverse, and plants should be earning their space with flowers, berries and winter color, for example.”
“Check to see if all the seasons are covered for interest,” she says. “Plantings should be diverse, and plants should be earning their space with flowers, berries and winter color, for example.”
Irrigation Systems
No irrigation system — even a high-tech smart one — is foolproof. Make it part of your seasonal maintenance routine to check your irrigation system regularly. “Sprinklers should be checked frequently, since they are above ground and can easily get damaged or misdirected,” Scott says. “Replace spray heads if necessary and clear any obstructions that block sprinkler spray. Adjust sprinkler heads so they don’t spray walls, driveways or sidewalks.”
Drip irrigation systems also need regular fine-tuning to make sure they’re doing their job. Scott advises running the drip system long enough to show the emitters’ wetting patterns. “Check from the valve to the end of the irrigation line for leaks or clogged emitters,” she says. Replace or unclog any as needed. Scott recommends doing this check about once a month.
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No irrigation system — even a high-tech smart one — is foolproof. Make it part of your seasonal maintenance routine to check your irrigation system regularly. “Sprinklers should be checked frequently, since they are above ground and can easily get damaged or misdirected,” Scott says. “Replace spray heads if necessary and clear any obstructions that block sprinkler spray. Adjust sprinkler heads so they don’t spray walls, driveways or sidewalks.”
Drip irrigation systems also need regular fine-tuning to make sure they’re doing their job. Scott advises running the drip system long enough to show the emitters’ wetting patterns. “Check from the valve to the end of the irrigation line for leaks or clogged emitters,” she says. Replace or unclog any as needed. Scott recommends doing this check about once a month.
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Weeding
Pulling weeds is always on a gardener’s to-do list, no matter if the garden has been recently planted or has grown for years. To help suppress weed growth without using herbicides, consider choosing plants and plant combinations that spread to fill empty spaces, leaving little room for weeds. Cover any bare soil with mulch.
While most weeding is done over spring and summer, Scott says that in the dry-summer California climate, fall is often referred to as a “second spring.” She recommends that California gardeners pull weeds judiciously in fall to prevent seed heads from dropping and germinating over winter.
If you’ve identified an area of the garden that has a persistent problem with weeds and invasive plants, you may want to consider sheet mulching or “lasagna gardening,” in which layers of compost, cardboard and green material like grass clippings (nothing with weed seeds) break down over the winter to form a fertile topsoil. Weeds are suppressed beneath it.
Natural Ways to Get Rid of Weeds in Your Garden
Pulling weeds is always on a gardener’s to-do list, no matter if the garden has been recently planted or has grown for years. To help suppress weed growth without using herbicides, consider choosing plants and plant combinations that spread to fill empty spaces, leaving little room for weeds. Cover any bare soil with mulch.
While most weeding is done over spring and summer, Scott says that in the dry-summer California climate, fall is often referred to as a “second spring.” She recommends that California gardeners pull weeds judiciously in fall to prevent seed heads from dropping and germinating over winter.
If you’ve identified an area of the garden that has a persistent problem with weeds and invasive plants, you may want to consider sheet mulching or “lasagna gardening,” in which layers of compost, cardboard and green material like grass clippings (nothing with weed seeds) break down over the winter to form a fertile topsoil. Weeds are suppressed beneath it.
Natural Ways to Get Rid of Weeds in Your Garden
Soil Health
Building healthy soil is key for the long-term health of all plants in a garden. Over time, lawns and high-traffic areas can become compacted, and beds can become depleted of essential nutrients for plant growth.
Poor maintenance practices. Poor maintenance practices, including overfertilizing, using pesticides and herbicides, and blowing off the topsoil with a leaf blower, can also contribute to declining soil and plant health. Stopping any of these practices can be a first step in building healthy soil in a mature garden.
Building soil health. While it’s best to have your garden soil tested before planting (and correct any issues then), there are plenty of ways to help improve soil health in established gardens. “We top beds with seven-year seasoned horse manure every spring before planting,” Wheatley-Miller says, adding that her team also uses organic fertilizers and seaweed products throughout the growing season.
Building healthy soil is key for the long-term health of all plants in a garden. Over time, lawns and high-traffic areas can become compacted, and beds can become depleted of essential nutrients for plant growth.
Poor maintenance practices. Poor maintenance practices, including overfertilizing, using pesticides and herbicides, and blowing off the topsoil with a leaf blower, can also contribute to declining soil and plant health. Stopping any of these practices can be a first step in building healthy soil in a mature garden.
Building soil health. While it’s best to have your garden soil tested before planting (and correct any issues then), there are plenty of ways to help improve soil health in established gardens. “We top beds with seven-year seasoned horse manure every spring before planting,” Wheatley-Miller says, adding that her team also uses organic fertilizers and seaweed products throughout the growing season.
Soil compaction. Soil compaction is one of the issues Pell says he sees most in established gardens. Letting leaves fall to form a natural mulch, allowing plants to spread out and cover soil, and ceasing topsoil blowoff can help compacted soil start to heal. Lawns can benefit from core aeration.
To help break up heavy soils, Pell recommends adding calcium slowly over several years. (Gypsum is a common calcium-based soil additive used for this.) To replenish soil nutrients, Pell says, “high-quality compost teas, sea kelp and humates are important tools in our tool kit.”
Learn more ways to build healthy soil in your garden
To help break up heavy soils, Pell recommends adding calcium slowly over several years. (Gypsum is a common calcium-based soil additive used for this.) To replenish soil nutrients, Pell says, “high-quality compost teas, sea kelp and humates are important tools in our tool kit.”
Learn more ways to build healthy soil in your garden
Lawns
Over time, lawns often become compacted and grass plants start to show signs of stress. Bare spots, yellowing patches and areas with more weeds or moss than grass plants are all common issues with established lawns. Start by addressing soil health and compaction. If you can’t stick a stake in your lawn, it’s compacted.
Soil compaction. Wheatley-Miller recommends using a core aerator to help with drainage and compaction issues. She says her team applies compost to help feed a lawn naturally. Raking can also help break up moss in lawns and lightly aerate the soil.
Over time, lawns often become compacted and grass plants start to show signs of stress. Bare spots, yellowing patches and areas with more weeds or moss than grass plants are all common issues with established lawns. Start by addressing soil health and compaction. If you can’t stick a stake in your lawn, it’s compacted.
Soil compaction. Wheatley-Miller recommends using a core aerator to help with drainage and compaction issues. She says her team applies compost to help feed a lawn naturally. Raking can also help break up moss in lawns and lightly aerate the soil.
Fertilizers. Pell strongly advises clients against using chemical-based fertilizers on their lawns. “You will probably just destroy your lawn,” he says. Instead, hire a professional or use organic fertilizers. “You generally won’t overfertilize a lawn with organic fertilizers,” he says, adding that humates and compost teas “can be your best friend.” Apply each according to the directions on the package.
Best lawn care practices. Other lawn care best practices the pros advise include watering less frequently but more deeply to encourage strong root growth, allowing grass to grow longer between mowings (particularly in summer) and reseeding to fill in bare patches.
8 Sustainable, Organic Practices for Greener Lawn Care
Best lawn care practices. Other lawn care best practices the pros advise include watering less frequently but more deeply to encourage strong root growth, allowing grass to grow longer between mowings (particularly in summer) and reseeding to fill in bare patches.
8 Sustainable, Organic Practices for Greener Lawn Care
Trees
Given that tree care varies depending on climate, site and tree type, it’s best to work with an arborist for tree care in mature gardens. An arborist can help address specific problems, advise on irrigation schedules and prune trees for long-term garden health.
Watering. Generally speaking, there are a number of best practices for keeping trees healthy. Around the tree, build good soil that is uncompacted and rich in nutrients. Most trees (save for those that thrive in dry summer climates) benefit from an occasional deep watering throughout the growing season. Watering stakes can be driven into the soil and used to slowly release water to the tree roots. Move them to positions from the trunk of the tree to the drip line and turn the hose on very low for about an hour for each position for a slow soak.
Soil compaction. In general, try to keep off tree roots to avoid soil compaction and to facilitate airflow to roots. This includes avoiding topping tree rings with heavy rocks and surrounding a tree with hardscape. Additionally, Wheatley-Miller says to avoid mulching around the tree trunk, as damp mulch touching the bark can cause rot.
Given that tree care varies depending on climate, site and tree type, it’s best to work with an arborist for tree care in mature gardens. An arborist can help address specific problems, advise on irrigation schedules and prune trees for long-term garden health.
Watering. Generally speaking, there are a number of best practices for keeping trees healthy. Around the tree, build good soil that is uncompacted and rich in nutrients. Most trees (save for those that thrive in dry summer climates) benefit from an occasional deep watering throughout the growing season. Watering stakes can be driven into the soil and used to slowly release water to the tree roots. Move them to positions from the trunk of the tree to the drip line and turn the hose on very low for about an hour for each position for a slow soak.
Soil compaction. In general, try to keep off tree roots to avoid soil compaction and to facilitate airflow to roots. This includes avoiding topping tree rings with heavy rocks and surrounding a tree with hardscape. Additionally, Wheatley-Miller says to avoid mulching around the tree trunk, as damp mulch touching the bark can cause rot.
Pruning. Pell says mature trees benefit from careful pruning to open up the tree canopy to more light and allow for airflow. Pruning “can do a lot to show off the beautiful structure of a tree or the layers planted beneath,” he says. For any significant pruning, it’s best to hire an arborist.
Failing to prune trees can result in changing the environment of your garden in the long run. For example, Pell describes planting a garden with a shrub layer beneath shade trees. While the shrubs may receive the perfect amount of sun in the first few years of a design, 10 years later the trees will have grown and created an environment that’s too shady for the shrubs. “So, you can let your beautiful Rhododendron calendulaceum [shrubs] die a slow death, or you can move them to a more ideal location or prune the trees above them and appreciate [the rhododendrons] for years to come,” he says.
Pell says it’s ideal in most cases to prune trees for shape and size when they are dormant. “Most trees are resilient and can even be pruned in the summer as long as it’s minimal,” he says. “If you need to make significant cuts in the summer, help the tree by irrigating it a bit if the soils are dry.” For fertilizing trees, Pell recommends using organic matter such as leaf compost, humates, compost teas and kelp.
Failing to prune trees can result in changing the environment of your garden in the long run. For example, Pell describes planting a garden with a shrub layer beneath shade trees. While the shrubs may receive the perfect amount of sun in the first few years of a design, 10 years later the trees will have grown and created an environment that’s too shady for the shrubs. “So, you can let your beautiful Rhododendron calendulaceum [shrubs] die a slow death, or you can move them to a more ideal location or prune the trees above them and appreciate [the rhododendrons] for years to come,” he says.
Pell says it’s ideal in most cases to prune trees for shape and size when they are dormant. “Most trees are resilient and can even be pruned in the summer as long as it’s minimal,” he says. “If you need to make significant cuts in the summer, help the tree by irrigating it a bit if the soils are dry.” For fertilizing trees, Pell recommends using organic matter such as leaf compost, humates, compost teas and kelp.
Shrubs and Hedges
The long-term care a shrub will need depends on the type, so it’s best to work with a local professional to address any specific issues.
Soil compaction. To break up compacted soil around an existing shrub, use a rake or spade to throughly break up the top 3 inches of soil; this will allow water and oxygen to better reach shrub roots. Then top with mulch or compost, keeping it away from trunk. Some shrubs, such as boxwood, have shallow-growing roots that do not like to be disturbed. In this case, loosen the soil gently with your fingers or a small trowel and top with mulch.
If you’re using an organic fertilizer such as kelp meal to feed shrubs, sprinkle it below the mulch or compost layer on the loosened soil and water it in.
The long-term care a shrub will need depends on the type, so it’s best to work with a local professional to address any specific issues.
Soil compaction. To break up compacted soil around an existing shrub, use a rake or spade to throughly break up the top 3 inches of soil; this will allow water and oxygen to better reach shrub roots. Then top with mulch or compost, keeping it away from trunk. Some shrubs, such as boxwood, have shallow-growing roots that do not like to be disturbed. In this case, loosen the soil gently with your fingers or a small trowel and top with mulch.
If you’re using an organic fertilizer such as kelp meal to feed shrubs, sprinkle it below the mulch or compost layer on the loosened soil and water it in.
Pruning. Each of the landscape experts we interviewed cited incorrect pruning of shrubs and hedges as one of the most common problems they see in gardens.
In general, best pruning practices aim to increase light and air circulation, which are crucial to plant health, and to control plant size and shape. Wheatley-Miller advises to always keep a thicker base and slightly narrower top when shearing hedges. She says that this tapering technique allows light to reach the bottom tier of the plant and helps prevent snow damage in winter.
If your mature hedge plants develop a dead-looking twiggy center as a result of constant shearing, check your pruning technique. Pell says that selective “windowing” of a sheared shrub (making select cuts into the center of shrub with a hand pruner after shearing) can help increase light and air circulation. This helps prevent a dead-looking center from forming and can help rectify it in mature plants.
Take Care of Your Hedges With These Pruning Pointers
In general, best pruning practices aim to increase light and air circulation, which are crucial to plant health, and to control plant size and shape. Wheatley-Miller advises to always keep a thicker base and slightly narrower top when shearing hedges. She says that this tapering technique allows light to reach the bottom tier of the plant and helps prevent snow damage in winter.
If your mature hedge plants develop a dead-looking twiggy center as a result of constant shearing, check your pruning technique. Pell says that selective “windowing” of a sheared shrub (making select cuts into the center of shrub with a hand pruner after shearing) can help increase light and air circulation. This helps prevent a dead-looking center from forming and can help rectify it in mature plants.
Take Care of Your Hedges With These Pruning Pointers
Perennials
Dividing and transplanting. A few years after planting, some perennials can benefit from dividing and transplanting. For those that are short-lived or have been damaged, it’s time to replace them.
While it depends on the type of plant and the growing conditions in your garden, Wheatley-Miller says the time to divide clump-forming perennials is usually after four to five years, or when clumps start to have dead centers. “Perennials can get overgrown, and dividing produces healthier plants and more diversity in plant communities,” she says.
While dividing, Pell adds, it’s a great time to remove the roots of any weeds that have become entangled with perennials. Perennials you’ve divided can be replanted in other areas of the garden, given to friends or neighbors, or donated to local organizations.
Dividing and transplanting. A few years after planting, some perennials can benefit from dividing and transplanting. For those that are short-lived or have been damaged, it’s time to replace them.
While it depends on the type of plant and the growing conditions in your garden, Wheatley-Miller says the time to divide clump-forming perennials is usually after four to five years, or when clumps start to have dead centers. “Perennials can get overgrown, and dividing produces healthier plants and more diversity in plant communities,” she says.
While dividing, Pell adds, it’s a great time to remove the roots of any weeds that have become entangled with perennials. Perennials you’ve divided can be replanted in other areas of the garden, given to friends or neighbors, or donated to local organizations.
“If it’s a short-lived plant, like lavender, and it comes out of the winter looking bad, it may take a lot of time and energy to get marginal results,” Pell says. While he notes that he appreciates why many people hesitate to pull out plants even when they’re failing, he urges his clients to take a practical approach: “Just replace that plant and enjoy your growing space.”
The same goes for plants that can aggressively take over in the garden by spreading clumps or self-seeding. “Herbaceous plantings can seed around, and certain plants can outcompete others,” Pell says. “We must intervene at times to keep the diversity that may have been planned in a garden.”
The same goes for plants that can aggressively take over in the garden by spreading clumps or self-seeding. “Herbaceous plantings can seed around, and certain plants can outcompete others,” Pell says. “We must intervene at times to keep the diversity that may have been planned in a garden.”
Natives and Drought-Tolerant Plants
Natives and drought-tolerant plants require more supplemental water as they get established in gardens, but too much irrigation can harm them later on. “After the second summer or third summer — depending on the amount of rain received during the wet season — most natives or other low-water plants will be fully established,” Scott says of the California plants she works with. “Those natives that are fully drought-tolerant will no longer need supplemental irrigation, except during dry winters.”
She finds that most plants, including succulents, look lusher in gardens with some supplemental irrigation. “You can also mist the plants with water occasionally to wash dust from the leaves,” she says.
Natives and drought-tolerant plants require more supplemental water as they get established in gardens, but too much irrigation can harm them later on. “After the second summer or third summer — depending on the amount of rain received during the wet season — most natives or other low-water plants will be fully established,” Scott says of the California plants she works with. “Those natives that are fully drought-tolerant will no longer need supplemental irrigation, except during dry winters.”
She finds that most plants, including succulents, look lusher in gardens with some supplemental irrigation. “You can also mist the plants with water occasionally to wash dust from the leaves,” she says.
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All three landscape experts we interviewed agree that as plants grow in and gardens change from year to year, some editing is essential. The key is to balance intervening with sitting back and enjoying the natural change.
Observe your garden as it changes. Finding this balance in your own garden starts by taking the care to see the changes in your landscape. “We must step back and see what is happening,” says Donald Pell, principal designer at Donald Pell Gardens in Phoenixville, Pennsylvania. “This process of gardening is not just pulling weeds but creating your idealized version of your habitat. You, as the owner, gardener and designer, can always look and learn to see what is happening and how you might want to intervene in succession.”
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