- Author: Susan Rosenthal
This cross between Chilopsis (desert willow) and Catalpa was introduced just a few years ago and is the only shrub form Chitalpa. Growing 5 to 8 feet tall and 3 to 4 feet wide, it produces pinkish purple orchid- or snapdragon-like blooms in spring and sporadically throughout summer. After one season, my five-gallon plant is now 4 to 5 feet tall.
Recommended for sun to partial shade, mine gets about five hours of afternoon sun but would probably like a little more to bloom better. We'll see as it gets older. One thing for sure, the hottest afternoon sun in July didn't phase it. In slightly sandy soil it's doing well with average water. Anyone familiar with the older Chitalpa trees knows their big downside — constant leaf drop all summer long. Because of that, I was really hesitant to try the shrub. But no problem! This one hasn't lost a leaf all summer, and foliage has stayed bright green with no scorching even at 114 degrees.
- Author: Susan Rosenthal
Gray green succulent foliage forms a clump 12 to 18 inches tall and up to 3 feet wide. Brilliant magenta flowers, showy from quite a distance, are carried on 1 to 2 foot stems above the foliage. Each inflorescence is reblooming, so resist the urge to deadhead until completely spent.
Very easy to grow, Calandrinia is said to prefer full sun, but in our area a little afternoon shade can prevent sunburned leaves in the hottest part of summer. It needs a lighter soil with good drainage and very little water once established.
Overwatering will definitely kill this one. A closely related species, Calandrinia grandiflora, is somewhat larger than spectabilis and distinguished by its narrower more elliptical leaves. Both are great, just be aware when buying. More cold hardy than many succulents, Calandrinia can tolerate temperatures down to 20 degrees without damage.
As older leaves die off, plants can become a little leggy. If so, cut back in late winter. It may be best to replace plants periodically, and fortunately propagation from cuttings is easy. Calandrinia is an excellent choice for a xeriscape or rock garden and also good in containers. Basically, this is one you can plant and forget (almost).
- Author: Susan Rosenthal
Bletilla striata, or Chinese ground orchid, is an easy-to-grow terrestrial orchid that performs exceptionally well in our area. Completely dormant in winter, Bletilla is just beginning to emerge now and by mid- to late-spring will be covered with small cattleya-like blooms in shades of purple, pink or white. Sword-like pleated foliage 12 to 18 inches tall remains attractive throughout the summer. Bletilla prefers damp (not wet), well-drained soil enriched with organic matter. It does best with morning sun (to produce flowers) and afternoon shade in our summers.
Ground orchids grow from corm-like pseudo bulbs that serve as nutrient storage for over-wintering, so continue to provide moisture throughout the growing season. Allow foliage to die back naturally and apply a good organic mulch in autumn. Virtually disease free, although snails and slugs are an occasional problem. Bletilla will naturalize over time, and clumps are easily divided in late winter.
- Author: Susan Rosenthal
Few plants outperform pink knotweed, Polygonum capitatum, in the fall. The plant blooms throughout the spring and
summer, but it's in autumn when most things in the garden are finished that pink knotweed really shines.
This groundcover spreads quickly and can cover a large area, but regular edging can easily keep it in check. The plant is considered invasive in warmer coastal regions of California, but not in our area. Burgundy tinged foliage and pink/red
stems are attractive even when not in bloom.
Pink knotweed grows in sun or shade. In our area, it appreciates some afternoon shade in the summer, so Polygonum works well as an under planting for trees and shrubs. It looks best with regular water, but is fairly drought tolerant once established.
Additional facts:
- Tolerates poor/sandy soil
- Hardy in zones 7-11
- Foliage will die back with a hard freeze but returns quickly in the spring. Remove dead foliage/stems by cutting to the ground in late winter.
- If space is limited, Polygonum can be used in raised beds or containers, where it will trail attractively.
- Author: Susan Rosenthal
Chaste trees (Vitex shrubs Vitex agnus castus) are extremely popular in our area and for good reason - they are consistently great performers. So, it's surprising that Vitex shrubs are so infrequently seen, a missed opportunity to be sure.
Vitex trifolia and Vitex rotundifolia are both good shrubs, but flowers are insignificant and growth habit can be a little unruly, taking some effort to control. But crosses of these species with Vitex agnus castus have yielded exciting hybrids without these problems. Vitex ‘Flipside' (agnus castus x trifolia), Fine Gardening Magazine's shrub of the year in 2019, is a 6- to 10-foot shrub with much larger flowers, extremely long bloom time, neater habit and an interesting purple tint on the underside of its leaves.
Vitex ‘Summertime Blues' (agnus castus x rotundifolia) has the interesting rounded foliage of rotundifolia but much more prominent flowers and a dense compact growth habit reaching 6- to 8-feet tall. ‘Delta Blue' and 'Montrose Purple' are among others in the 8- to 10-foot range, but all can be kept smaller with a late winter pruning.
Other new dwarf varieties including ‘Blue Diddley,' ‘Pink Pannicle,' and ‘Blue Puffball' stay under 4- to 6-feet. All do well in full sun with average well drained soil and are drought tolerant once well established. Very few pest or disease problems. Smaller dwarfs do very well in containers. Vitex shrubs can occasionally be found at local garden centers but are more readily available by mail order.