If you garden in USDA zones 4 through 9, ‘Storm Cloud’ bluestar will grow well for you with one important caveat—this perennial requires 10 to 12 weeks of temperatures below 40°F to bloom. If you live where the winter weather won’t provide that necessary cold, you could grow it simply for the attractive foliage.
This durable perennial holds its own in average soil and all-day sun or part sun, meaning a place that receives a minimum of four hours of afternoon sun. If you grow it in too much shade or in rich soil, you won’t be as happy with it. Though bluestar is fairly drought tolerant once established in your garden, it will flourish with some moisture. While it can certainly handle windy, exposed sites, you may need to water a little more often there.
‘Storm Cloud’ grows more than three feet across as it matures but rarely requires division, so look for a permanent location when planting. You are more likely to notice this perennial in nurseries when it is blooming in the spring, but stores tend to stock it all season. You can plant it any time of year if you can keep it watered well that first season.
If the roots are densely circled around when you take it out of the pot, loosen them up a bit to break the “root memory”. This will encourage them to grow outward instead of continuing to grow in a circular pattern.
No special soil is needed for bluestar. However, if you garden in heavy clay, it’s a good idea to amend with shredded bark or soil conditioner to improve the drainage. Any soil amendments you use should total less than one-third of the soil used to backfill the hole. It would be detrimental to the plant to only use “good” soil in the hole when backfilling.
A good rule of thumb is to dig your hole twice as wide and just as deep as the plant’s rootball. When you backfill the hole, press the soil down with your hand firmly to remove any big air pockets around the roots. Then, water the plant to help the soil settle around it.