As Dr. Spock famously said about parenting: “Trust yourself. You know more than you think you do.” This is equally true about gardening, even for beginners. People sometimes ask me when they should pick vegetables, as if it was a total mystery, and I generally reply that they’ll know it when they see it, especially if it’s a crop that’s commonly available in markets and grocery stores. If not, a quick online search or a look at the seed packet or catalog may enlighten you. Yours may not achieve the shiny perfection of the catalog models, but it’ll be recognizable. There are exceptions to this easy-to-tell model (melons are notoriously enigmatic) but mostly it’s not so hard.
Being ready to pick and eat, however, is not the same thing as being ripe, and this is a matter of great confusion among even some experienced gardeners, so I’ll plant a few ideas here that might help. Or make you more confused. I don’t know, I can’t think in this heat either.
As we watch the high temps stubbornly refuse to budge, it’s tempting to hunker down indoors and let our gardens go. Don’t. Those plants really need us now.
The best thing you can do to help is to water well. That means watering deeply less often.
Water at the base of plants to soak the roots. Photo: Miri Talabac, UME
Daily sprinkles do more harm than good, stimulating shallow roots, which have a harder time drawing up the water plants need.
Light watering also encourages tomatoes and peppers to develop black, leathery blossom end rot.
So water vegetable plants deeply twice a week. Dial it back to once a week when things cool down.
Watering in the morning is best as is directing water to the base of plants.
If you planted new trees or shrubs this year, water them slowly and deeply at least once a week to soak the root ball. Use a soaker hose, a 5-gallon bucket with a few nail holes, or a hose on a slow trickle.
Tree bags help to keep trees and shrubs well watered. Photo: Joe Murray, Bugwood.org
If you’re growing anything in containers, check those pots daily. Most need to be watered every day. And do some supplemental watering in your perennial beds. Everything is dry, dry, dry.
Smart tools make watering easier and use less water.
Soaker hoses – made from recycled tires – water plants slowly at the base of plants so you don’t lose water to evaporation.
Drip irrigation does the same and lets you customize water zones. I can’t say enough good things about the drip irrigation system on a timer in my vegetable beds.
Drip irrigation saves time and money. Photo: Robert Cook
Rain barrels are a godsend. An eighth of an inch of rain on the average roof fills a 50-gallon barrel. That’s free water, folks. I have four rain barrels and plan to add two more.
Rain barrels capture rain from roofs to reduce water bills. Photo: Rutgers University
Avoid watering with sprinklers. Overhead watering can promote disease and cause the loss of up to 80 percent of water to evaporation.
Here are some more tips on conserving water and using smart tools.
In addition to boosting plants’ water needs, heat zaps plants in other ways.
Have you noticed flowers falling off your tomato plants? Sustained high temps prevent pollination, causing plants to jettison their blooms. Don’t worry. Flowering and fruiting will restart when it cools.
Trees react to high heat, too. Many are raining down leaves. This is a natural stress reaction. In fact, trees don’t need all their leaves. They’re just shedding some to cut down on maintenance.
Unless the leaf loss is dramatic, those trees will be just fine.
Lawns are feeling the heat as well, browning here, there, and everywhere. They are not – I repeat not – dead. Lawns naturally go dormant in high heat and will spring back with rains. Only new lawns need to be watered.
If you’d like to boost your landscape’s resistance to heat and drought – and the need for supplemental watering – add some water-wise plants.
Deep-rooted, well-adapted native plants are a great choice. So are plants with fleshy leaves or roots, blue leaves, skinny or fuzzy leaves – all natural adaptations that mean these plants need less water. Think sedum, iris, lavender, threadleaf coreopsis, and lamb’s ear.
Watering wisely and picking the right plants will help you build a more heat-resilient landscape that can not only beat the heat but look good doing it.
By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.
Arborvitae (Thuja sp.). Photo: Jason Sharman, Vitalitree, Bugwood.org
Q: I need to reduce the height of an arborvitae…. I might take around 5 feet off the top because it’s too big. When should I prune?
A: While late winter or early spring is generally a good time to prune conifers (needled evergreens), in this case timing won’t matter much, because the amount you want to remove is more than the plant can handle. Instead, it may be better to replace the plant with a smaller-growing option.
Most conifers, including arborvitae, do not regrow foliage when it’s lost due to heavy pruning, deer browsing, or crowding from being planted too close together or too close to a wall or fence. Unlike broadleaf evergreens (boxwood, holly, euonymus, etc.), they don’t have dormant buds along the older stems, lying in wait to grow if the branch or foliage beyond them is removed.
Once the foliage is gone and bare wood is visible, it’s not coming back on that part of the plant. This is the reason why deer-browsed arborvitae are easy to spot, developing a shape sort of like a stemmed flute glass, because the parts the deer can reach become stripped of foliage and never fill back in again, even as the out-of-reach tops get wider.
As conifers age, it’s perfectly normal for the innermost branches to become quite bare, as those older leaves shed over time. They are deliberately jettisoned by the plant because they are being progressively shaded by the outer shell of live growth, so they cost the plant more to keep alive than the meager photosynthesis energy they get back. This will be exacerbated if the plant is sheared, where the foliage tips are lightly trimmed to give the plant a more manicured look, because that makes the layer of foliage casting shade on the plant’s interior even denser.
Pruning cuts that take off that outer layer or shell of younger growth on the branch tips will result in permanent bare areas. Once the foliage is gone from that inner wood, it will not regrow, even if sunlight now reaches the interior due to pruning cuts. This also applies to the main leaders. Reducing the height of a tall arborvitae will stunt the top growth and give it a permanent gap or flat-looking top. If this isn’t really visible from where you typically view the plant, then it’s not necessarily a problem (assuming the pruning cuts seal-over well and don’t develop wood decay). Otherwise, nothing will give the plant its former shape back.
Fortunately, there are lots of compact and dwarf conifer varieties on the market these days. A couple conifer types, like yews, will be able to rejuvenate after heavy pruning. Even so, it’s still best practice to select a plant that should fit in a given space in the yard without relying on pruning to make it fit.
I acknowledge that there are many gardeners that inherit poorly-chosen plants in their new yards, but if or when it comes time to replace them, research your options to make sure you won’t run into the same problem down the road. Plants never really stop growing, though older specimens can slow down. Due to a reduced growth rate, dwarf and miniature cultivars will stay much smaller over the same amount of time as their full-size counterparts, even though some dwarf cultivars can also get larger than you’d expect a few decades after planting.
By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.
Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask Extension. Our horticulturists are available to answer your questions online, year-round.
Just a quick post this month to shout out the virtues of the first tomato plant to produce ripe fruit for me this year: ‘Veranda Red’ patio tomato.
This little cutie is only 18 inches high, and in fact would be shorter if it was growing in full sun instead of the partial sun on my deck. I have other plants with green fruit ready to turn red that are less than a foot high, and the container team at the Derwood Demo Garden has a plant only about six inches high that has ripe fruit.
Patio tomatoes as a group mature at less than two feet, and grow well in smaller containers like window boxes or gallon pots. The larger the pot, the larger and more productive the plant will be, but they will be loaded with flowers and fruit even in a small container. Most varieties are cherries, though a few make larger salad tomatoes.
‘Veranda Red’ is a relatively recent hybrid, but some patio tomatoes have been around for years. A few varieties I found in a quick search include ‘Tiny Tim,’ ‘Micro Tom,’ ‘Tumbling Tom’ (and the rest of the Tumbling series), ‘Orange Hat,’ the ‘Patio Choice’ series, ‘Red Robin,’ and there are many others. Try doing a search on ‘patio tomato’ or ‘micro dwarf tomato,’ or check your favorite seed catalog. You may also find plants at a garden center (I know Bonnie Plants has their own variety and others are likely available – just read the tags carefully to make sure you’re getting a dwarf plant).
These tomatoes are a great option for folks who don’t have much growing space, maybe a balcony or window box or a postage-stamp sunny patio or yard. They don’t produce as much as a full-size plant, but more than you would think!
Now, I have a bunch of full-size tomato plants already growing in my community garden plot, none of which have ripe fruit yet, but they’re getting there. Why bother with patio tomatoes? Well, sometimes a plant, like a person or a pet, just fills a particular spot in your life. Fifteen months ago I inherited a cocker spaniel named Freckles who used to belong to my mom and stepfather. She’s made a new home with us and definitely found a home in our hearts. Freckles loves many fruits and vegetables and is especially fond of tomatoes – she can sniff out the plants well before they have any fruit and will drag us to them. Last year she hunted for fallen cherry tomatoes around our neighbor’s big potted plants and alerted me to some volunteers that sprouted in unexpected spots in my landscape. So I thought it would be nice if she had her own tomato plants closer to home. We make a stop on the deck after a walk to see if any new ‘Veranda Red’ cherries have appeared. She approves!
By the way, I did get to eat one of the tomatoes myself, and can report that it was very tasty. Recommended, even if you don’t have a tomato-eating dog.
By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.
I know most folks don’t like creepy-crawlies. Bugs aren’t their thing. Mine, yes, but this is what I do – help people deal with garden pests and protect good bugs.
Some good guys do look scary, like something out of a sci-fi movie with spikes and fangs and ridges and crazy colors.
But looks aren’t everything. In most cases, these are good bugs – what we call beneficial insects – that help to control the few bad dudes in your garden.
Let me introduce you to a few bug friends that aren’t beauties but do a beautiful job of controlling harmful pests.
Assassin bugs get a bad rap simply because of their name. We’re talking James Bond, right?
Scary-looking assassin bugs are efficient predators. Photo: Photo: Johnny N. Dell, Bugwood.org
That’s a good thing. Assassin bugs are efficient predators, but boy, do they look scary. Battleship grey with spikes down their backs, they look like they’re wearing armor.
But the battle is mostly one-sided. Insects that cross an assassin bug’s path likely will get skewered by its lance-like mouthpart and slurped dry.
Stop shuddering. There’s an upside.
Assassin bugs eat almost any bug, making them ecological balancers that keep insect populations in check. Plus, they enjoy snacking on Japanese beetles, the scourge of many a garden.
Cute and beneficial, the ladybug lies at the other end of the beauty spectrum. But as youngsters, ladybugs resemble tiny orange and black alligators which often get squished because they look like they are Up To No Good.
Spiky ladybug larvae control aphids and other pests. Photo: Whitney Cranshaw, Colorado State University, Bugwood.org
Not true. These are good guys who consume even more aphids, spider mites, scales, and other baddies than adult ladybugs. In fact, one ladybug can eat over 5,000 aphids in its lifetime.
Many juvenile insects look nothing like their more familiar adult counterparts. So stop before you squish or spray. Snap a photo or bring a sample to your local Extension office. Most likely it’s an ally you want to protect.
You can find your Maryland Extension office on our website. Or reach out to the certified horticulturists at our Home & Garden Information Center for help. Send a photo or question to them at Ask Extension.
Wasps get a bad rap, too, with much swatting and shrieking and fear of The Stinger. Only females have those – they’re modified egg-laying organs – and they aren’t likely to use them unless threatened.
But most wasps are beneficial, preying on bad bugs or laying their eggs on them to feed their young. Plus, they are pollinators, protecting 1 in 3 bites of food we eat.
Scoliid wasps lay their eggs on Japanese beetle larva. Photo: Shanon Wolf
Spiders aren’t insects – they have 8 legs, not 6 – but they give many people the willies. But spiders also are beneficial, quietly and efficiently consuming many harmful insects.
Argiope spiders provide free pest control in the garden. Photo: Heather Lawhead
Beauty isn’t everything. An army of not-so-lovely-but-useful insects are your allies in the garden, protecting your plants from the 1 in 10 bugs that are actually harmful.
So think before you squish or spray. Get us a photo or sample. We’ll identify it and give you management tips that deal swiftly with bad bugs while protecting beneficial insects.
By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension.
Each year, the spring and summer seasons seem to go faster and faster, and 2024 is no exception. If you have a lilac shrub, you can probably still imagine the sweet fragrance and beautiful flowers from a few months ago. I get several questions each year about lilacs, so the blog today is going to answer some of those inquiries!
A few years ago, we decided to begin excavating for our new garage in late summer, and unfortunately, had to move a lilac shrub. The transplanting was not as high of a priority as it should have been, and the shrub suffered tremendously the following year. We gave it a season to see if it would recover, but ultimately, it was too damaged. At that point, we decided to try rejuvenation pruning and cut everything back to 6” above the soil line in hopes that the shrub would come back and have a better overall shape and appearance. We had nothing to lose as the plant was suffering, not growing, and not flowering.
A lilac that was transplanted at the wrong time of the year and damaged. Photo: A. Bodkins, UME
Question: What is rejuvenation pruning?
Answer: Lilac rejuvenation pruning involves cutting the entire woody shrub back to a few inches above the soil surface. This can be done if a shrub is really scraggly or if you want to change its shape entirely. Last summer, my parents had to do a construction project behind their very large, 20+-year-old white lilac, and they had to cut it back to the ground. It seems to be rebounding just fine, though!
March 8th: First sign of life on the rejuvenation pruning. Photo: A. Bodkins, UME
June 4th: Regrowth progress. Photo: A. Bodkins, UME
Question: My lilac has not bloomed for the last several years. What could be wrong? It used to be beautiful each spring!
Answer: Lilacs need full sun to bloom. Often in people’s landscapes, as trees mature, lilacs get less sun than they once did, leading shrubs that once produced abundant, full blooms to have limited to no blooms.
Question: Why did my lilac bloom in the fall?
Answer: Environmental stress can cause out of season blooming. Some examples include drought, excessive heat, defoliation from pests, heavy pruning, insects, or diseases.
Question: What time of year should I prune my lilac?
Answer: Many spring-blooming, woody shrubs will set the flower buds for the next season’s growth in late spring or early summer, so be sure to prune for shaping and maintenance purposes as soon as the shrub is finished blooming for the current growing season.
For more information on lilacs, see the Home and Garden Information Center’s page, Lilac: Identify and Manage Problems — particularly the sections on diseases, insect pests, and heat-tolerant and powdery mildew-resistant varieties.
We tend to think about protecting our insects when and where we see them. This is perhaps why we may have a higher propensity to think about protecting pollinators we can see flying around rather than organisms that live in the darkness of the soil or hidden in the leaf litter. In today’s post, I would like to bring some attention to other groups of insects we may tend to forget about but which we can also help protect: insects that are active at night.
Don’t insects sleep at night?
Although many insects are generally less active at night due to the lower temperatures and their inability to move when the temperatures drop below a certain threshold, many insects are adapted to being active at night. For example, if they are pollinators of nocturnal or dusk-flowering plants such as several moth species are, they will be active when darkness falls. Other insects are active at night as predators, or at certain times of the season looking for mates and egg-laying sites. For all these insects, the absence or reduced presence of light is important for allowing them to take on what they need to do to survive and/or reproduce. For this reason, the presence of artificial night lighting in our outdoor spaces, especially in the warmer periods of the season, can interfere with these insects, leading to potentially very negative effects.
How can outdoor night lighting affect nocturnal insects?
Insects can be perturbed in different ways through outdoor night lighting. One of them is its potential interference with their temporal rhythms. In fact, like most animals, insects use light-darkness and the presence of certain night sky cues (e.g., full moon) to regulate their developmental cycles and perceive the progression of the season. The presence of supplementary lights during the night hours can lead to altered developmental cycles, making them longer or mismatching those of organisms belonging to the same species. This can lead to the insects missing their optimal mating times, losing their ability to forage on specific plants, or properly preparing for the arrival of colder nights as the season progresses.
The use of often non-essential lighting, such as light strings and other nocturnal accent lights in our spaces, can negatively affect the development, survival, and reproduction of many nocturnal insects. Photo: P. Danilyuk (CC)
Another issue that artificial nocturnal light can produce relates to the spatial disorientation of nocturnal insects. This can occur when insects are attracted to nocturnal light sources instead of moving towards their optimal habitat. This can lead to increased predation in those areas (the insects become more exposed to being seen), as well as their spending valuable energy by spending time in an inhospitable region. Further, disorientation can happen in a more indirect way by the light’s interference with the patterns present in the canopy. In fact, many insects have been shown to use the contrast pattern of the canopy and the sky to navigate and identify optimal habitats. The presence of nocturnal artificial lights can lead to the disappearance or a stark modification of that contrasting pattern, interfering with their ability to find their way in the ecosystem and decreasing their ability to find a proper habitat for their survival.
Some insects like fireflies use bioluminescence for inter-species recognition and mating. Photo: T. Ota (CC)
In some cases, the presence of nocturnal artificial light can interfere with mating and intraspecific recognition behaviors. Many groups of insects, such as fireflies and glow worms, use light cues to attract and recognize each other. In regions such as ours, where fireflies represent such an important part of our ecosystem, the use of outdoor nocturnal artificial lighting can interfere with the finding of mates and can potentially lead to much reduced abilities to reproduce and sustain populations.
What can we do to reduce this type of nocturnal pollution?
The obvious answer to this question is that if we want to reduce this type of pollution, our best bet is to turn off non-essential outdoor night lights, in particular during times of the year when insects are active. Doing this may actually save us some money, but also will allow us to support a higher diversity in our area, all while potentially letting us appreciate even more the nocturnal activity that may be present in our region. For example, doing this may make it easier to support fireflies and participate in their conservation, but can also support the reproduction of plant species that depend on nocturnal pollinators.
If leaving lights on is unavoidable, one should consider the intensity that is being used. Can the light be dimmed to a lower intensity? Could it be filtered to display a color that is less disruptive to insects? The Xerces Society has put together a really neat guide on this (Firefly-Friendly Lighting Practices – PDF), and I strongly encourage you to consult it if interested.
Finally, another way we can contribute to reducing unnecessary night lighting is by engaging in our communities. Initiatives such as DarkSky can help with this, both promoting best practices at the community level and engaging in conservation through community certification programs that are conservation-effective. You can learn more about these nocturnal conservation programs here.
By Anahí Espíndola, Associate Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.
Anahí also writes an Extension Blog in Spanish! Check it out here, extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!
