June 2025 Gardening Advice

Peonies. Photo courtesy of Jennifer Fairfield.

by Jennifer Fairfield, Garden Mill

OK – what the ever-loving heck is with our weather?! Never mind – it’s Michigan. I know that Michigan weather is never predictable, so I don’t know why I let it get to me when it does exactly what it always does at this time of year — mess with me. It’s enough to drive a gardener crazy, if you let it. So, I’m going to try meditation. Maybe some calming music. And then I’ll get out there with my tools and get to work getting my veggie garden going before we run out of gardening season!

If, like me, you have been waiting for the weather to straighten out so that you can get your vegetable garden going and plant some annual flowers without worrying that the cold nights are going to stunt their growth, it looks like we’re in luck with the upcoming week. Take advantage of the heat and sun this month to get everything done that you haven’t been able to do yet!

In the veggie garden:

• It finally looks like we can safely plant our warm-weather plants later this week, and not a moment too soon, as we have a pretty short growing season in Michigan. So, don’t wait much longer to plant tomatoes, peppers, eggplant, basil, rosemary, and other transplants. When transplanting, give your veggies a leg up with a fertilizer that contains mycorrhizae, like Espoma’s Bio-Tone Starter Plus. Mycorrhizae is a fungus that helps your plants take up nutrients and water. Your plants return the favor by providing the fungus with sugars through photosynthesis. What does all this mean for you? Giving your plants some fertilizer with mycorrhizae in it at the time of planting can help them get established more quickly, grow better, and produce better. It also helps feed the soil, which in turn helps feed your plants. So, it’s a win-win-win. I don’t do any transplanting without it, and that goes for anything that I’m transplanting — not just veggies, but annual flowers, perennials, shrubs, and trees, too.
• Plant seeds for everything else you want to grow in your gardens that doesn’t get planted as seedlings. This includes corn, beans, carrots, beets, cucumbers, squash, etc. You might be able to get away with a late planting of radishes and leaf lettuce, if you have a spot in your garden that gets afternoon shade. Otherwise, wait until late summer to do a succession planting of those and spinach, which don’t do well in the heat of summer.
  
• Plant seeds of carrots, bush beans, dill, and cilantro every week or two. This way, you can be sure to have a continuous harvest throughout the season. Be sure to read the package information about how long each variety you are planting needs to mature. Figuring that our first frost usually hits around October 15, you can determine how late you can plant things, and still hope to get a good harvest, by counting back from there. For instance, if what you are planting says “days to germinate = 7 to 10” and “days to harvest = 60” then you know you need at least 67 to 70 days before you will get anything from this plant. That means that you need to make sure that you plant those seeds no later than August 9th to ensure that you will have something to harvest before cold weather sets in.
• Be sure to immediately and thoroughly water anything you plant, and make sure the soil is kept moist where you sow seeds. Newly transplanted plants aren’t as efficient at taking up water as those that have been in the ground for a time, and can easily get dried out. Seeds also need moisture in order to germinate, so be sure to give the whole garden a good drink whenever we aren’t getting sufficient rain.
• For anything that needs support, get stakes or cages in at the time you plant so that you don’t damage roots later. To help you with that, all plant supports are on sale this month at The Garden Mill! Be sure to spread mulch around everything at the time of planting, too. Mulch does a number of great things for your plants — it keeps the soil temperature consistent, suppresses weeds, helps retain moisture, and helps prevent soil-borne diseases from spreading to your plants. So, don’t skip that step!
• Spray tomatoes, cucumbers, and squash with an organic fungicide early and often. I am totally in love with Bonide’s Revitalize these days, and I’m not alone. I recommended it to a friend last year, and he reported that their plants “lasted much longer than any other year in memory!” Begin as soon as you get the plants in the ground, and follow the manufacturer’s instructions for frequency (usually weekly). We have had a lot of disease pressure in recent years, and I don’t think that’s going to get any better. Treating for things including blight, powdery mildew, and downy mildew from the beginning is the only way to stop them from ruining your gardening season, as these diseases can only be prevented, not cured. Good airflow through the garden is also important in disease prevention. It helps things dry out in between rains, which helps keep spores from growing, so be sure to space your plants out as well.
• Weeding is an important part of keeping your plants healthy and producing too, even if it’s not everyone’s favorite chore. Weeds compete for water and nutrients, and they can also be disease carriers. Doing a little weeding every time you’re in the garden can make it seem a little less tedious, and getting weeds before they get too big is so much easier than waiting until they are towering over everything.

In the flower garden:

• Plant summer-blooming bulbs if you haven’t already. This includes dahlias, gladiolus, lilies, begonias and canna lilies.
• Wait to trim back the foliage of your spring blooming bulbs, such as daffodils, tulips and alliums, until the foliage has died completely. Although you may be tempted to trim them sooner to tidy up, leaving the foliage will help the bulb use the sun’s energy to feed itself for next year’s blooms.
• June is prime planting time for perennials and annuals, but be sure to water them well when you plant them, and keep them well-watered throughout the season. As with vegetables, newly planted flowers don’t take up water easily from the soil, so giving them regular waterings will keep them going. Perennials will be spending the summer putting out lots of roots so that they can be well-established when winter hits. Annuals, on the other hand, will spend the season putting on a show — they know they won’t make it past this season, so they concentrate on putting out flowers, which produce seeds for their next generation. Keep those flowers deadheaded, and they will just keep on producing more flowers in an attempt to produce seeds. Just remember that all that flower production needs water and fertilizer. There are a number of varieties of annuals that have been bred to not need deadheading in order to continue blooming. This includes most petunias, begonias, most impatiens, annual lobelia, and some zinnias. Annuals should be fertilized regularly throughout the season. Perennials generally only need one application of fertilizer each spring. For both types, a low-nitrogen, high-phosphorus fertilizer is best. Too much nitrogen can produce lots of foliage, but not a lot of flowers, and can cause some plants to get leggy and flop over.
• Container plants also need to be watered and fed regularly. As containers fill up with roots, they don’t hold water very well, so you need to be sure to give them water on a regular basis, which often means at least daily in the heat of summer. And, since the plants are in a container, they can’t get their nutrients from the soil around them, unless you provide it. Just be careful not to over-water or over-fertilize, especially with chemical fertilizers. Too much of a chemical fertilizer can “burn” your plants — a sure way to kill them. Too much water will drown them and flush out fertilizer.
• Keep an eye out for pests in the garden as the season really gets going. I’ve already seen aphids on my asters, and I know it won’t be long before the Japanese beetles make their annual appearance. Follow some basic rules if you are using any kind of insecticide to deal with pests. First — be sure that you know what sort of insect you are dealing with, as how to treat them differs, depending on what it is. Second, keep in mind that any insecticide has the potential to kill beneficial insects as well as the bad ones. So, don’t do broadcast spraying — target your spraying to just the pests you are trying to get rid of. Also, spraying in the late evening, and only using organic insecticides that don’t persist on the plants for very long, can help prevent unintentionally killing bees, which tend not to be active at night because they don’t have good night vision. That doesn’t mean that you won’t potentially harm other beneficials in the evening, so really, the best thing to do is limit spraying as much as possible. If you’re not sure what is best for your situation, come talk to me — I’m always happy to help.

Trees and shrubs:

• Once your forsythia, quince, and other early-blooming shrubs have finished blooming, prune them back. Pruning encourages new growth and more flowers next spring.
• Don’t “seal” pruning wounds when you prune trees. The old way of thinking was that you needed to do this in order to keep diseases from setting in. Newer information has shown that it isn’t effective and can actually cause more problems by keeping the area moist. The only time sealing is recommended now is if you prune an oak tree any time other than in the dead of winter. The reason for this is that the flowing sap of a freshly cut oak can attract insects that carry oak wilt disease, which is deadly to the tree.
• You can pinch back evergreens once they have put out new growth. Pinching the new “candles” back by half will encourage them to bush out. But don’t cut into old wood, as most evergreens won’t produce new shoots from old growth.
• Be sure your trees and shrubs have a good layer of mulch over their roots to keep them evenly moist and prevent weeds. Mulch should extend out to the tree’s dripline (the area under the tree’s leaves) but not be placed right up against the trunk. Piling mulch up against the bark can lead to disease and pest problems.
• Water trees and shrubs if we aren’t getting sufficient rain. Newly planted trees and shrubs should be carefully watered for the same reason newly planted flowers need to be – they aren’t as good at taking up water while the roots are getting established. But be careful about how you water any tree or shrub. Water infrequently, but deeply. You want to encourage the roots to grow deeply, which won’t happen with frequent, shallow watering. Additionally, shallow, frequent watering can cause your plants to suffocate and slowly die.

For the Birds:

• When you are out in your yard, keep an eye out for things like killdeer nests (they build their nests on the ground), and be careful to keep activity away from them as much as possible. Also watch out for baby birds that have left the nest but not yet mastered flight. They probably don’t need your help, unless they are somewhere where they might be in danger, like in the road, but do watch for them as you go about your yard work to be sure that you aren’t putting them in danger with things like power equipment.
• The Baltimore orioles have been super active at my feeders lately, but I know that they will disappear soon. It’s not that they actually leave, but once babies hatch, they are busy collecting and feeding insects to their young. My feeders are still out though. The hummingbirds are happy to drink from them, and once the oriole babies are out of the nest, the parents may bring them to the feeders to help them fatten up for the trip south.
• Clean out and refill hummingbird and oriole feeders regularly. Sugar-water left out in the hot sun can quickly spoil, and become bacteria-filled. If it’s really hot, empty, clean and refill the feeders every two to three days. During cooler times, be sure that you clean out and refill the feeders at least weekly. Also clean out other bird feeders weekly to help keep diseases at bay.
• Remember to clean out and fill your bird baths regularly, too. Birdbaths provide your birds with a place to get a drink or a good bath, and provide you with lots of entertainment, as you watch them playing in the water. Birdbaths are also a breeding ground for mosquitoes, so emptying them, cleaning them out, and refilling them every day is a good idea not just to help keep birds healthy, but also to keep mosquito eggs from hatching.

For as little as $1 a month, you can keep Manchester-focused news coverage alive.

by Sara Swanson

Sara Swanson is an editor, writer and founder of the Manchester Mirror.