Blue Star Creeper plant (Isotoma fluviatilis) is a low growing, evergreen ground cover and can be quite invasive.
Blue Star Laurentia (Isotoma axillaris) is a taller plant that bears similar blue flowers but does well as a bedding plant and is much easier to control
While Isotoma axillaris is only winter hardy in USDA hardiness zone 11, Isotoma fluviatilis is hardy to zone 6 and thrives as a perennial in many parts of the United States.
It also reseeds itself freely and will grow naturally and abundantly as an annual in full sun.
Blue Star Creeper Care
Size & Growth
Blue Star Creeper tops out at about 6″ inches high. Individual plants should be spaced 18″ to 24″ inches apart as the growth rate allows them to spread very rapidly.
Flowering & Fragrance
This attractive ground cover produces a wealth of small, star-shaped white, light blue or dark blue flower color blooms. Flowers are unscented yet seem to be attractive to butterflies, wasps, and bees.
It blooms abundantly from mid-spring until early winter in warmer climates. Deadheading is unnecessary.
This evergreen plant has smooth, green foliage color. Under ideal circumstances, it can form a dense, green carpet, tough enough to handle substantial foot traffic.
The plant is extremely resilient and could tolerate mowing and other management typical of lawn care.
Light & Temperature
Blue Star Creeper does well in many different sun exposures. It is an excellent choice for every sun exposure ranging from light shade to full sun.
It is tolerant of a wide range of temperatures but performs best in a consistently warm climate.
Watering & Feeding
This plant needs average water regularly. Be careful not to overwater this drought tolerant plant.
Occasional deep watering is preferable to frequent shallow watering.
Fertilize very little or not at all to prevent invasive tendencies. A single application of all-purpose garden fertilizer early in the spring is more than adequate.
Soil & Transplanting
This plant does well in almost any soil. It tolerates pH levels ranging from mildly acidic to mildly alkaline (6.1 through 7.8). As with most plants, light, well-draining soil helps prevent problems with root rot.
Grooming & Maintenance
There is no need to deadhead to encourage flower production. Mow or shear to one inch in height late in the autumn to avoid a raggedy appearance through the winter months.
Propagating Blue Star Creeper
It’s hard not to propagate Blue Star Creeper. Plants also spread on their own via underground runners and reseed themselves with wild abandon.
This plant can be propagated by dividing the root ball.
It’s best to do this early in the spring and plant out the small individual plants in plenty of time for them to get a good foothold and begin to spread.
It is also possible to collect seeds by allowing seedpods to dry on the plant. Collect the pods and break them open to harvest the seeds.
Scatter seeds early in the spring after all danger of frost has passed, or you may start plants indoors six weeks before the last predicted frost. Remember to transition plants carefully to the outdoors.
Blue Star Creeper Pest or Disease
Blue Star Creeper tolerates a wide variety of adverse conditions.
But it will never look its best when growing:
- In too little light
- Too much water
- Very poor quality soil
- Other deficits
It can handle foot traffic, but this will take a toll on its appearance.
Overwatering can cause root rot and may attract slugs, snails and grubs which may feed on the plant stems and roots.
Is the plant considered toxic or poisonous to people, kids, pets?
Keep kids and pets away from Blue Star Creeper because all parts are toxic if ingested. Additionally, people with sensitive skin may experience an allergic reaction when handling the plant. Be sure to wear gloves.
Is the Plant Considered Invasive?
Blue Star Creeper is said to have naturalized in many temperate areas along the United States West Coast, and Florida and throughout the southeastern United States.
The plant grows rapidly and spreads freely through underground runners. It tends to pop up many feet away from the parent plant and will overtake your grass or your garden if given half a chance.
If you’re going to plant the Blue Star Creeper plant, be sure you can contain it.
In fact, it’s a good idea to keep it as a container plant and carefully control it and prevent self-seeding.
Although deadheading is not necessary for bloom production, it is recommended to prevent voluntary reseeding.
Once the plant is established, getting rid of it is nearly impossible. Digging only encourages small roots in the ground to become whole plants.
Suggested Blue Star Creeper Uses
This plant does well in rock gardens, alpine settings and used as a ground cover perfect for garden pathways around stepping stones and rock walls.
Although Blue Star Creeper is very tough and grows naturally and enthusiastically in many areas of the US, it is not always reliable as a groundcover.
Under ideal circumstances, it forms a dense green mat with lovely white or blue flowers. Under less than perfect circumstances, it grows thinly and looks patchy.
Additionally, anecdotal evidence indicates that it doesn’t do a very good job of blocking weeds. Weeds are apparently able to grow right through it.
For the most part, gardeners who have given this rambunctious plant a try seem to regret it.
If you do decide to try Blue Star Creeper, it is wise to contain it, deadhead regularly to prevent seed development and dispose of any cuttings in a very thorough and responsible manner such as burning.
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