Early July Garden Q & A

Our customers are asking questions…and we’re here to help!

At Hyannis Country Garden we’re here to identify plants, answer questions, and help our customers solve their problems. Here are a few of the questions that people have brought into the store or sent us by email in the past week.

Q: Why isn’t my Hydrangea flower opening? There are only petals on the edges.

A. Your Hydrangea is one of the varieties that we call “lacecap.” Lacecap blossoms have two types of flowers: there is a ring of showy, sterile petals around the outside and a group of smaller, fertile flowers in the center. These are completely different from the mophead types that are a ball of sterile flowers. You might notice that the bees are all over the inner, fertile parts of these blooms. Some lacecaps develop in color over the summer, so enjoy that transition as the season goes on.

Q. Why are there white lines on the leaves of my columbine?

A. Those lines that you see indicate the presence of the columbine leaf miner (Phytomyza aquilegivora). This is a fly that lays its eggs on the leaves about the same time that the columbine comes into flower. The eggs hatch and the larvae go into the foliage, tunneling in between the upper and lower leaf tissues. This doesn’t kill the plants (columbine are short-lived anyway) and we view this as a cosmetic issue only.

Q. What are these flowers that are blooming on the corner of my neighbor’s property?

A. These are the flowers of Yucca filamentosa, a native plant on Cape Cod. You might have noticed the spiky leaves under these blooms. Yucca is a very drought tolerant plant that thrives in full sun. The flowers attract hummingbirds. This plant is able to grow in pure sand, and is drought tolerant.

Q. I have a black coating on my holly bush. What is wrong?

A. Your holly has scale. The black coating is called sooty mold, and is growing on the plant juices that the scale excretes. There are a couple of different scales that you might find on holly – one is white and looks like tiny pieces of cotton, and the other are very small tan dots. In either case, the response should be the same. Spray the undersides of your holly leaves with horticultural oil (aka All Seasons Oil) or Neem Max. Mix the products according to directions and spray two or three times during the summer. Next year, put it on your calendar to spray in the late spring.

Q. My Hydrangea has white stuff under the leaves. Is that also scale?

A. Yes. Although it’s not common on Hydrangeas, it does appear now and then. Treat with horticultural oil as described for the holly above.

Q. Why can’t I grow Lavender? It always dies in my yard.

A. There are a few reasons that lavender might not do well. Here are the things that this plant needs to thrive: Good drainage….plant lavender where they are in full sun and well drained soil. Secondly, don’t put it where the automatic irrigation hits it frequently. Water lavender deeply, once a week. Since lavender loves heat, it does especially well by a stone patio, gravel areas or a stone wall. And finally, plant the varieties of lavender that do well on Cape Cod: Munstead, Super Blue or Phenomenal.