Tidy up, test your soil and watch for disease

There never seems to be enough time in any given day to get everything done! I have not yet finished spring cleanup in my garden.

If you are running late as I am in getting your garden cleaned up, continue removing garden debris from beds and cutting back perennials.

Since perennials have begun growing, be very careful when cutting them back and removing debris to avoid damaging new growth. Cut perennials back higher above ground to protect the new growth. I am less aggressive with pruning shrubs at this time of year.

Apply fertilizer to garden beds if needed. Most gardens in the Chicago area have soil with adequate levels of phosphorus, so choose fertilizer with little or no phosphorus. The higher the percentage of nitrogen in the fertilizer you purchase, the less you need to apply to your garden. Follow instructions on the bag, and don’t be shy about asking a salesperson in your local garden center for advice.

Have your soil tested if you want to be sure you are selecting the best fertilizer for your garden. Mix soil from a few locations for a good composite sample when you do the soil test. If your garden is large, break up your property into sections and send in multiple samples.

I have seen some winter burn on evergreens this spring. It’s time to prune off sections that are completely dead to allow the plants to fill back in. Cut them back to live wood with green leaves and then decide whether you want to keep the plant depending on its appearance. Evergreens tend to be slow to fill back in.

Some beds of pachysandra are showing evidence of a disease called Volutella blight. It begins as small, tan to brown circular spots that form on the leaves and enlarge to form blotches. You can see concentric patterns that form within the brown spots on the leaves as they turn yellow and fall off. The stems can also become infected and turn a brown to black color. I have seen completely dead and flat sections of pachysandra within big plantings this spring. The disease tends to be worse in wet areas in the garden. Clean up dead and diseased plants as best you can and put in the garbage. Do not put diseased foliage in your compost. If the disease is not severe, the pachysandra will likely recover. Spraying pachysandra with fungicide may benefit in some garden situations.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.