Garden almanac

In the Garden this Week

Iron chlorosis on an Amur Maple leaf

Some shrubs and lawns are yellowing in the garden this week. The leaf or blade is a yellow color with green veins. Iron chlorosis is a tie-up of iron in the soil due to higher temperatures. While the iron is in the soil, the plants cannot take it up into their leaves. Some varieties like silver maples, amur maples, some of the viburnums, and some lawns with heavy clay soils are more prone to this condition. The use of hose-attached liquid chelated iron helps reduce the condition.

Apple maggots

On apples and pears, there has been a lot of coddling moth larva damage in the fruit. Usually, they start at the stem end and burrow through the center. There is an apple maggot out there that burrows in the side of the fruit. It may be too late to do anything about it now. Next year if you have apples, get on an orchard spray schedule reading the directions starting early in the season. This also helps with scab and rust fungi.

Rust fungus on grass blades

If you are walking through the lawn and stir up dust, it is a rust disease. Rust has been troublesome this year. Rust causes orange to black spotting on grass blades and leaves. If you are watering, let the area dry out completely, reducing the spores. Fungicides prevent this, but it is too late now.

Powdery mildew on squash leaves

Another fungus is powdery mildew which looks like talcum powder sprinkled on the leaves. Lilacs will get this; however, it rarely harms the plants. In the garden is another matter. I get it on the vine crops every year is I do use a fungicide as a preventative.

With the coming cooler temperatures, September is a good time to use a parameter barrier spray around the home. It helps to keep the bugs and spiders from finding shelter in your house.

Onions are ready to store when the tops fall over and 2/3 have turned yellow. Dig up and allow them to dry for a couple of weeks in the shade before storing them. I set them on a window screen under a tree and bring them in if it is going to rain.

Coneflower
Lead plant
Liatris
Yarrow

Last week I wrote about grasses making a good planting in hot, dry areas with poor soil. Some perennials to use if you want flowers are yarrows, lead plants, cone flowers, and Liatris. There are many other tough perennials you can buy. 

Interesting note: did you know apples and pears descended from one fruiting tree. They separated and through generations became two fruits.

Garden almanac, Garden Pests

In the Garden this Week

A couple of things have been going on in the garden this week with the tomato fruits. One is the skin cracking. The cause is a sudden influx of water to the fruit causing it to expand splitting the skin. A mulch of organic matter like straw helps to cool the soil and consistent moisture. Some varieties like cherry tomatoes and the early maturing varieties are more prone to this condition.

The other is blossom end rot where the bottom of the tomato fruit turns brown and leathery. This is caused by a tie-up of calcium in the soil due to inconsistent wetness and dryness with high temperatures. Again, mulching helps, and it seems the tomato will grow out of this condition when it gets cooler. Some varieties are more prone to blossom-end rot like Early Girl.

With the higher moisture we have been getting and now cooler temperatures, mushrooms are popping up in some lawns. What you see is the fruiting structure of the fungus; the fungus itself is under the ground. It grows on old, rotting tree roots left in the ground. It is a part of nature and there is nothing you can really do but wait a few years till the tree roots are gone. Mowing them off is good, if you have pets think about removing them from the lawn at ground level.

The aphid population has exploded with the high temperatures. Aphids are species specific meaning aphids on asters will not go to roses. You get full-pressure water from a hose and wash them off. If the infestation is bad, you can use insecticide soap, Neem oil, or Malathion. Apply when the temperature is cool, read the instructions on the label. The ants herd the aphids like cattle, “milking” or collecting the honeydew secreted by the aphid as food. The same sticky stuff falling from the trees on your car.

If you use a plastic sprayer for a herbicide like Roundup or 2,4-D, do not use it for a fungicide or insecticide. It is very hard to clean the sprayer to remove the herbicide residual. Get another sprayer for nonherbicide applications.

Blue Fescue
Blue Gamma Grass
Big Blue Stem
Miscanthus

Lastly, if you have an area that you cannot get anything to grow in, try native grasses. I have used Big Bluestem, Miscanthus, and Blue Fescue, and they turned out great. They take heat, drought, and poor soil in stride. Others are Switch Grass and Blue Gamma Grass.

Garden almanac, Garden Pests

In The Garden This Week

Let’s talk about a few garden things in the garden this week. Leave hail damage garden plants and flower plants alone. By now you should see what is dead or dying so remove them. Most plants will set leaves and reflower, we have plenty of time left. Trees with split trunks should be removed. If over ½ of the tree is gone, consider removing and replacing it. For slightly damaged trees, trim to the nearest large branch or trunk. Keep well-watered but let the fertilizing go till next year. Do not paint over any wound, let the air dry it out.

Late blight on tomato plant.

There have been a lot of lower leaves on tomato plants yellowing and drying up, you might be dealing with early blight. It’s a pesky fungus that thrives in hot, humid weather. The best way to manage it is by applying a fungicide to protect the unaffected leaves, especially after it rains. And if you’re watering, try soaking the ground instead of watering overhead to keep things in check. You might start using a fungicide if they were wounded by the hail.

Now, onto weeds. Roundup, which is now made by Bayer, has been a go-to for nonselective weed killing. Its active ingredient, glyphosate, is also available under other labels now that its patent has expired. The key difference? The concentration of the active ingredient. Roundup usually ranges from 41% to 50%, but you can find generic versions with up to 54% glyphosate. Just be sure to read the mixing instructions carefully!

Needle cast disease on evergreens.

If you’ve got pines and notice the older needles dying, especially on one side, it could be a needle cast fungus. While fungicides can help, they must be applied early in the season. For now, just keep your trees well-watered.

And don’t forget to keep deadheading (removing dead blossoms) your annuals like snapdragons, coleus, marigolds, zinnias, and daisies to keep them blooming until the first frost.

Puncture vine.

Lastly, the weed of the week is the puncture vine. It’s sneaky and can be painful if you step on it barefoot or in stockings. You’ll usually find it in gardens, flowerbeds, or along gravel roads. The best solution? Hoe it out and never let it set seeds.

Dragonfly on a coneflower.

On a brighter note, dragonflies are out in full force, which means mosquito populations are dropping!