Cathy Olson
Adam's County Master Gardener Program

Good answers to gardening questions come from a variety of different sources. A neighbor of mine in Carroll Valley, Pennsylvania has been the Nursery Specialist at a Big Box store in Westminster, Maryland for 13 years. Following are the questions that he most often encounters from his customers.

Early Spring/Summer Questions

Which plants, annuals or perennials, come back each year? We'll start with an easy one: annuals have to be replanted each year, and perennials come back by themselves.

When is the best time to plant grass seed? In our climate it’s September or October. Second best time is April or May.

When is the best time to put down crab grass preventer? As last year's crabgrass seeds germinate in February or March, this is the best time to apply a herbicide that will kill them.

When is the best time to use "weed and feed"? When the weeds are actively growing, at bud stage.

What can I plant that deer won't eat? Ornamental grasses, herbs, coral bells, wild native plants (wild ginger, wild geraniums, Lenten roses, false forget-me-nots) are some plants deer do not like.

Should I prune my lilacs before or after they bloom? Immediately after blooming, to maintain the size of the shrub. Rhododendrons too. Take off no more than 1/3 of the growth. When watering, do so at ground level. To help prevent diseases, do not get water on the leaves.

When should I prune my roses? February and March. Prune the brown deadwood down to the ground and the green wood down to 6" above the ground. Growing roses is not for the faint-hearted; they need lots of attention, regarding placement of plants (all day sun), spraying for disease prevention, and pruning for health.

Why and when should I use mulch? Always use mulch: it conserves moisture, keeps weeds and soil-born diseases down and as it breaks down, it adds organic matter to the soil. Cedar and cypress mulches should be used close to the house because they are insect and rot resistant. Hardwood mulch breaks down the fastest.

Should I put rings of mulch up against my trees? NO! In spite of what you see in your neighbors’ yards, "mulch volcanoes" cause "mulch root" with roots looking for moisture above ground; they should be looking for moisture below ground for deep roots. This will help in dry years when water is needed most.

Summer Questions

How can I prevent heat-related diseases. To prevent heat-related diseases, use neem oil on plants that are susceptible to powdery mildew, black spot and other leaf diseases, e.g., lilacs and roses. Apply the neem oil in May every 7-10 days for 4 weeks.

How do I prevent blossom end rot on my tomatoes? Blossom end rot is caused by lack of calcium and uneven watering. Do not let tomato plants dry out entirely. Use lime (spread on soil or mix with soil) when planting tomatoes.

What can I do about the ants in my kitchen? The safest and most effective treatment is Boric Acid dust or gel; place a line of it where you see the ants so they will take it back to their nest. It will kill them.

How can I keep my fresh cut flowers lasting longer? The white powder preservative that you buy kills the bacteria that prevent the stem from getting water to the flower.

How do I keep Japanese beetles out of my garden? Their grubs live in your lawn. Kill the grubs with milky spore by spreading it, by hand, on your grass. Do not use beetle traps; they attract all the Japanese beetles within a quarter-mile of your house to your garden. If you do use beetle traps, keep them as far away from your garden as possible.

Should I spray all the insects I see in my garden? NO. Many of them are beneficial insects; they are needed as pollinators for your plants, and they eat other, often harmful insects. Some examples of beneficial insects are lady bugs, soldier beetles, lace-wings, and assassin bugs.

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