How to get a handle on weeds

Q. I had two large ivy beds in my front yard and decided I wanted all ivy removed as many weeds where taking over. It was a massive undertaking. My workers dug up everything, sprayed with weed killer, then spread pine straw.

Now that hot weather is here, weeds are back. I’ve tried three different sprays, and nothing is working. It kills for a while, and then weeds are back. I hate using all these chemicals. Is laying a black tarp over the ground my only solution to conquer these weeds?

A. I cannot tell you that you will conquer weeds. It just takes persistence. The weed population is huge, and they spread by various means, including roots that weed-killers fail to eradicate, wind and birds.

You will always have to face some weeds; the goals are to keep the numbers as low as possible and to use a minimum amount of herbicide.

There are two basic kinds of weeds: annual, which spread by seeds from flowers that are allowed to develop, and perennial weeds, which spread by seeds and roots.

With annual weeds, such as chickweed, you must get the plant out, by digging or herbicide, before it sets seeds and produces a new generation that will sprout sooner or later.

With perennial weeds, you must dig them up or use an herbicide that kills roots as well as the stems and leaves. And it sometimes takes more than one application.

What you are seeing is probably a combination of warm-weather perennial weeds and fresh crops of annual weeds.

I once had a large bed of ivy, since removed (except for a few odd spots) and now planted in shrubs and perennials. A pine tree produces a nice layer of fresh needles every year and weed control has been minimal. But I keep a close watch for young weeds that are easy to pull up, especially after a rainfall when the ground is soft.

Landscape fabric, which allows rainfall to move through, could help you keep the weeds under control. You can cut holes to set out shrubs and trees you want. However, weed seeds can still blow in and erupt in the mulch. The battle goes on.

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Q. The spring has gotten away from me, and I just realized that I never fertilized my camellias and rhododendrons. Is it too late to do so now?

A. It is too late, and it is not necessary. If those plants look good, they should be fine. The more important thing is to keep the plants watered during dry weeks through the summer. Good, organic soil, excellent drainage and two inches of pine needle mulch are the essentials for these plants. Too much fertilizer is far worse than too little.