Overview and Description:
- Flowers: The cup-shaped flowers are a pale green as they start to open, but quickly turn purple or white, as they fill out. The opening buds have a somewhat unpleasant scent, but the fully opened flowers develop a floral-honey fragrance. The green calyces remain at the base of the flower and become the saucer.
- Leaves: Bright green, oblong leaves - and plenty of them.
Common Names:Cup and Saucer Vine, Cathedral Bells, Monastery Vine
ExposureThis vine really needs full sun, to bloom well.
Mature Plant Size:
Bloom PeriodYou'll get a lot of vine growth, early in the season. Flowers don't usually come along until mid- to late summer, but they'll continue into the fall.
If you'd like color earlier in the season, you can plant other annual vines as companions.
Planting: You will rarely find seedlings of Cobaea. The vines grow too quickly and become very tangled. You can direct seed, after all danger of frost or get a head start by starting seeds indoors, 6 - 8 weeks before your last frost.
Since the vines will get entangled, I recommend starting them in separate pots. You will also find it helpful to insert a twiggy trellis immediately, to keep them under control.
The seeds are large, flat and tough. Soaking them in water, the night before planting, seems to help speed germination. Germination can be erratic, but you should see sprouts within 2 -4 weeks.
When planting, tuck the seeds into the soil vertically, with the longest edge facing down, and barely cover with soil. Don't worry too much about positioning the seeds perfectly, but placing them flat and covering them with soil can cause them to rot. They also prefer a warm soil (70 - 75 F.) Heat mats or placing the seed trays on top of the refrigerator will accomplish this.
Maintenance:Young Cobaea plants are sensitive to the cold. Give them some protection if the temperature dips. Start training your vines early and they'll take it from there. If you would like to control its size, you can pinch the stems when they reach the top of your support or eye level. This will encourage branching and bud setting.
Keep the vines watered regularly, but don't let the soil remain wet. Go easy on the fertilizer or you will get a lot of vine growth and few flowers. If necessary, side dress with compost in mid-summer.
There is no need to deadhead the flowers or trim the vines.
Pests & Problems:Cobaea can attract aphids, especially when the plants are young and succulent. Frequent blasts of water or a couple of treatments of insecticidal soap should control them.
Older plants can fall prey to spider mites, especially during dry weather. Again, hosing down the plants will help control the pests.