A Gardening Journal

The Best Season Ever: White Paintbrush in Bloom

Alright, it's true: I neglect my pot of white paintbrush for months at a time. Does it ever receive water while overwintering in the greenhouse? That's six months of maybe / maybe-not. Even when outside in a shady spot from May through October, rainfall might be it. 

 

Nonetheless, my baby clump of three years ago has thrived. When I introduced this eccentric but so-easy-to-grow species at the beginning of 2014, my entire colony displayed just three pairs of leaves. And only one pair was from a blooming-size bulb; the other two were the small starter leaves produced by young offsets. Even a one-gallon nursery pot was spacious.

 

Now those three have expanded to nine, and they nicely fill the pot. True, it's still about a one-gallon size, but let's celebrate progress where we find it. And six are producing flower stalks; back then, it was just one.

 

Haemanthus albiflos overall 102017 640

 

Vegetatively as well as reproductively, this colony is looking satisfied, indeed. Could it be that what I guiltily think of as neglectful watering is, from this plant's viewpoint, skillfully laissez-faire?

 

White paintbrush's thick bulbs and leathery leaves all suggest that it doesn't mind extended drought, especially when growing in the shade it tolerates. The winter dryness it experiences in the greenhouse also combines with the cool (but frost free) temperatures there, plus the short days and weak sun of November through early March, all help the colony achieve a healthy and long dormancy. More moisture during dormancy could encourage rotting. On the other end of the yearly cycle, the warmer temperatures and longer days of the summer encourage growth, but the shady spots where I place this containered colony ensure that the growth isn't so vigorous that it outstrips available water.

 

The result is the steady warm-season increase of the colony, plus a heavy, late-season burst of flowering. All good!

 

Next season, I'll experiment how even more generous circumstances might help the performance. In April, I'll unpot the colony, pull the bulbs apart, and repot them in a larger but still shallow terra cotta pot. These are known as azalea pots, because when grown in containers for forcing, those fibrous-rooted shrubs need a broad but shallow root run. Haemanthus albiflos is also happy with a shallow root run.

 

The azalea pot I'm considering is about twice the diameter of this one, which means about three times the soil volume. I'll set out the replanted colony in a somewhat sunnier spot than usual, so that speedier growth ensures that the roots penetrate that amount of soil completely. If there were a bottom layer of barely-rooted-into soil by the time the colony was returned to the greenhouse in the fall, it could stay damp enough to cause rotting.

 

Will the fresh soil and increased overall volume encourage even more flower stalks in the same season as the repotting? Or maybe such a radically reworked Haemanthus will need a season to settle down before resumption of flowering. Regardless, I'll have created an even larger vegetative display from the get-go. White paintbrush in New England is a thousand miles and more away from its nearest possible frost-free habitat in a garden: the Gulf Coast and Florida. This species' dense growth and thick overlapping leaves are unusual enough up here to make even a flower-free year exciting.

 

Here's a look at this colony of Haemanthus albiflos when it was much younger, plus how to grow it.  

 

 
 
FacebookTwitterRSS Feed

Stay in touch!

 

Sign up for twice-monthly eNews, plus notification of new posts:

 

* indicates required