Ageratum/blue mistflower
I suppose you all caught the fact that last week’s article was about this weekend. I seem to have lost a week here. Anyway, I should have been telling you all to give your lawns that last minute fertilizing for the summer. June 1 through September, the ordinance that prevents us from using nitrogen and phosphorus on our lawns goes into effect, so fertilize now before June 1. Lee County has been affected by water pollution from these nutrients, with algae blooms and fish kills, resulting in health problems and a negative effect on our economy. This especially includes water and impervious surfaces. A spreader deflector is required on spreaders in this time period.
A mandatory law always in effect is, stay away from bodies of water/wetlands with fertilizer by 10 feet, measured from the top of the bank. Exemptions are vegetable gardens that are 15 feet away from a body of water, and new plantings for the first 60 days.
As for the hurricane season I mentioned last week, Florida is on a winning streak, having gone nine years without a landfall hurricane of level 3 or above. Experts are predicting a quieter than usual 2015 season, a lull in hurricanes (we may get some of the usual storms) but, we hope they are right. Still, clip dead and weak branches of shrubs and trees, keep yards clear of loose items and empty containers where water has accumulated to keep mosquitoes from breeding.
I use to fill flower boxes with red geraniums, white petunias and blue ageratum for patriotic holidays. Memorial Day has just been such a holiday. When I moved to Florida, I heard people calling, what I thought was ageratum,” blue mistflower.” I figured they were one and the same, regional difference. It took awhile, but I learned the blue mistflower was a hardy native ageratum, Conoclininum coelestinum. The non-native ageratum is called, Ageratum houstonianum. This knowledge is where knowing the Latin names help you define which one you are talking about and looking at. They look very similar, well to me, identical, with their cluster tufts of small blue flowers atop triangular green leaves, but they have different needs.
Ageratum houstonium is also called “floss flower,” an annual in the Asteraceae family of the Ageratum genus. It grows about 6 to 14 inches high and loves full sun but survives in partial shade. The seeds are poisonous as well as all parts of the plant. Handling the plant can cause allergic reactions or skin irritation. The pollen may cause allergic reactions, also. Blooms come in many different colors, pale pink, blue-violet, violet/lavender, purple, white/near white, blooming in late summer and fall.
This fragrant herbaceous plant is attractive to bees, butterflies and birds and reseeds itself. This means it can be aggressive, but manageable and not known to be invasive, says the University of Florida. Do not cover the seed when sowing because light is necessary for germination, and it is usually planted in the fall here for winter and spring color. Deadhead old flowers to gain continuous blooms. Ageratum likes a neutral to slightly acidic soil; it is not salt tolerant but slightly drought tolerant, very drought tolerant once established. Fertilize sparingly. I read someone’s statement that cattle won’t graze them, so they dot barnyard pastures.
They can be used for edging, massing, rock gardens or in containers. The taller cultivars may be used in bouquets.
Bluemist (Eupatorium coelestinum or Conoclinium coelestinum) is, however, a loveable rascal, the darling of the butterfly world. Because it is a native perennial plant, it is easy to grow, flowering from mid-summer into autumn. Not only does it attract swallowtail butterflies, but skippers as their nectar source. It also attracts bees and insects on which birds love to feast. Mistflower makes a great groundcover, loving rich soil with organic matter, and mainly found in moist to wet sites, like low woods, wet meadows, stream banks and ditches.
E. coecelostinum is a bear to deal with in flower beds, being extremely invasive with its extensive creeping white rhizomes. t may appear to be weedy early in its growing season, but the fuzzy purple-blue or blue-purple, often called a brilliant blue, blooms come on strong by the fall. Baby blue eyes are astounding and so is the unique Bluemist. Underground rhizomes form clumps of the plants which can be aggressive but are easy to pull out. Cut back early in the summer to increase branching and more blooms. It also reseeds with seeds blowing in the wind, landing and sprouting wherever they’re blown.
Bluemist (hardy ageratum) blooms reliably, filling in garden spaces, giving a wonderful fall garden appearance. After obtaining height in the fall, they make excellent cut flowers.
Mistflower can be invasive if you don’t keep on top of them.
There is another ageratum to further confuse me – Ageratum conyzoides or better known as the “Billy Goat weed,” or “Tropical Whiteweed.” Same family as the other ageratums only it has white flower clusters and smelly leaves all covered with fine white hairs. An annual, it grows to about 3 feet. There are countries in which this is a medicinal plant for cuts, burns, sores (a styptic) and body rashes. Anti-inflammatory and antioxidant. It doesn’t seem to be as poisonous as the other ageratums; still, the unpleasant smell of the leaves makes me feel like avoiding it.
A rose is a rose is a rose, according to Gertrude Stein, but, ageratums are horses of different colors and habits.
Bless a tree and thank it. Stay stress-free and enjoy your summer.
Joyce Comingore is a Master Gardener; hibiscus enthusiast; and member of the Garden Club of Cape Coral.