All the crazy weather and fluctuating temperatures this summer has us seeing all sorts of things happening in the garden. The goal is always healthy plants because healthy plants are better able to deal with stress of all kinds. But we know sometimes things go awry.
Correct watering is essential during the summer months. Newly planted trees, shrubs, and perennials should be checked every day for the first week, every other day during the second week and every third day during the third week. Soil should be dry 1-2” under the surface before watering. For the rest of the summer, once a week should do it.
Annuals and vegetable plants will need more water. Even watering of tomatoes will keep them healthy.
The first step is maintaining an even moisture level. Newly planted trees and shrubs typically need the equivalent of 1” of water per week. The best way to get them watered is to turn your hose on a slow trickle and place it at the base of the tree for about 20 minutes. Don’t rely on your sprinkler to get them all the moisture they will need, hand watering newly planted trees and shrubs is best. For perennials and annuals, it’s similar, slow, deep watering is best and try to avoid the leaves if possible. All plants will appreciate getting watered in the morning so that the water on the leaves has time to evaporate before night.
Karen, one of our Trees & Shrub salespeople in Naperville, has a fun tip for an outing. If you are planning on planting a tree this year (or next), visit the Morton Arboretum to see the tree you’re interested in planting in its mature form. The Plant Clinic has a map of where trees and shrubs are planted throughout the property to help you find them.
We talked about Japanese beetles last week (article available from The Morton Arb) but you might also be seeing powdery mildew on some of your plants. Monarda, peonies, phlox, lilacs are some of the most susceptible. The recent warm temps and high humidity are perfect breeding grounds for this garden annoyance. It’s pretty easy to spot on your plants. You’ll see a white coating on the leaves. If you spot it early, you can treat it with Espoma Earth-tone 3n1 Disease control. (Always read the label for application rates and directions) If much of the plant is covered, for perennials like monarda, phlox, and peonies, you can cut back the whole plant by 1/3 to 1/2. Remember, those powdery mildew spores can overwinter so do not put them in your compost bin or leave them lying on the ground. For lilacs, there is not much you can do. Look at its branches. Do you need to remove any to improve air circulation?
Powdery Mildew on a peony.
Another common thing that we are seeing now on River Birch is that some of the leaves are turning yellow and dropping. This is perfectly normal. They send out extra new leaves in the spring and drop them in the summer. Just be sure it’s getting enough water—they don’t call them River Birches for nothing.
If you’re not sure what’s going on with your plant, you can always bring in a sample to our Tree and Shrub department and we can help diagnose the problem. Remember to put your sample in a Ziploc bag.
Perennial and rose gardens need deadheading in the summer. Once you remove the spent flowers it diverts its energy into root development or, for some plants, a second bloom. As a general rule, using sharp pruning shears, cut off the bloom and stem down to the next new bud or flower. If there isn’t a flower, then cut to the first lateral branch. Avoid leaving stems or stubs sticking up. Roses are the same, but for some winter interest, you can let the last bloom form rose hips to keep on the plant during the winter. If you have been regularly fertilizing your roses, it’s time to stop.
Take stock of your garden. How are things growing? Do you see any holes? It’s okay to plant trees, shrubs, perennials, annuals, well anything, in the summer! You just have to be diligent in your watering. For existing shrubs, your yard we do recommend waiting until spring or fall after the leaves have dropped.
If you want to keep your lawn looking good, (not necessarily super lush and green but also not brown) you don’t need anymore more than 1” of water per week.
Did we miss something? You are always welcome to come in and ask us! We’re happy to help you get your garden growing right! Here’s a bit of garden inspiration plucked from the internet to keep you going. “The green thumb gardener is someone who grows a lot of plants, kills a few without mentioning it to others, and keeps on planting!”
Posted on 7/14/2016 at 1:09:00 PM