Perennial possibilities

The amount of plant breeding and plant breeders seems endless. But will a newly developed cultivar behave the way it is designed? Will the perennial revert back to a parent plant in the cross? Will it become invasive in our gardens? Trials, time and planting in a garden landscape will be the “proof is in the pudding.”

Here are some perennial possibilities that will liven up your landscape. This short list are perennials that are not invasive and won’t revert back to a parent plant. These perennials have multiple purposes including providing nectar for pollinators, long flowering, non-invasive or sterile, drought tolerant and are low maintenance. Low maintenance means low or xeric water requirements once established, no fertilization required and few pests or pest free.

Nepeta x faassenii cv. ‘Select Blue’ is a sterile, compact perennial that will not shed seed everywhere and become invasive. It has no insect and disease problems. But if you have cats or cats in the neighborhood, it may attract cats. Fertilization isn’t necessarily required and it does need well-drained but moist soils. It is less drought tolerant than the other Nepeta cultivars. A pruning right before it starts to produce flowers can keep it compact and a pruning after the first flowers will help with more prolific bloom from May through September.

Nepeta x racemosa cv. ‘Walker’s Low’ isn’t really that low because it gets up to 30 inches tall. It is sterile and won’t produce seeds. It is also insect and disease free plant. ‘Walker’s Low’ thrives in dry soils and tolerates drought. Pruning is the same as ‘Select Blue’. This cultivar, ‘Walker’s Low’ is closer to the true catmint that cats love.

Nepeta ‘Six Hills Giant’ does live up to its name because it grows to three feet tall. However, it is still sterile and is drought tolerant. Unfortunately, ‘Six Hills Giant’ blooms in June and July. It can suffer from root rot if the crown of the plant is overwatered. Yes, cats find this plant alluring.

Achillea ageratifolia or Greek Yarrow is very prolific with its white flowers that bloom from May through June. This perennial grows best in dry to medium sandy soils. It needs to be well-drained or it can suffer from stem rot. It is not disease free because rust and powdery mildew are issues. Watering at the base of the perennial will help keep down the fungal spores. When water lays on the plant leaves for long periods of time, it sets up an optimal environment for fungal or bacterial problems.

Achillea clypeolata x Achillea ‘Taygetea’ parents of Achillea ‘Moonshine’ is an upright, clump-forming, compact perennial with deeply dissected fern-like foliage. The foliage has an aromatic smell and in most of its features resembles ‘Coronation Gold’. The flowers of ‘Moonshine’ are lighter yellow on a shorter plant. ‘Moonshine’ needs well-drained soils. It has disease issues such as rust, powdery mildew, botrytis and stem root. All fungal issues that come from placing this plant in poorly drained soils or over-watering the plant. It is a long blooming yarrow that starts in June and goes through September.

Achillea millefolium ‘Terracotta’ is much like ‘Moonshine’ with the exception of flower color of reddish brown. ‘Terracotta’ has the same fungal issues and blooms only from June through August.

Achillea millefolium ‘Red Velvet’ is a deep rose-red and is a mounding perennial that grows to a height of 30 inches. It does well in locations providing full-sun, even when there is poor soil. It grows in all soil types. It does have rust and botrytis as fungal issues. Aphids can be a problem as well, but aphids are widespread pest on many perennials, shrubs and trees.