Vireya Culture Roundtable, Southern California Chapter
In 1992 the Southern California Chapter held a roundtable on vireya culture. The following informative tips were recorded in the chapter's September 1992 newsletter.
Rooting medium: pumice, perlite, coarse peat; use heating cables. Leaving the rooting bed open, including evenings (not a closed container), works better. Sprinkle every morning.
Standard mix: ⅓ coarse peat, ⅓ fir bark, ⅓ perlite. Fred Renich's mix: add more perlite, less peat (50% perlite, 25-30% bark, 15-20% peat).
Fill the bottom one-third of the pot with perlite. It dries out faster, so water more often. Plants grow faster, flower faster.
Two days after watering, cultivate - loosen top soil of pot with probe. This aerates, helps dry the mix out.
Fertilize lightly every two weeks with tsp. per gallon of Miracid plus chelated iron. Alternatively, you can use 2 parts Miracid, 2 parts iron, 1 part Peter's. Hand water and use all blended fertilizer; the mixed fertilizer won't store; it absorbs water.
Water: Fred Renich has a reverse osmosis system to remove solids and salinity. Ventura County well-water has 300-1500ppm dissolved solids, which will kill plants in three months.
In beds, you use less perlite because the plants are more self-sufficient. They don't need as much water, so you don't have as many problems. ("In the ground" means raised beds, not Southern California soil.)
In containers, don't let the pot get hot. Don't let the sun beat on the sides of the pot. It's okay for morning or late afternoon sun to fall on top but not on their feet. Keep the feet cool.
For powdery mildew, use Bayleton every two weeks. Good air circulation is the best deterrent.
Pinching: the habit of vireyas is frequently upright, so you should pinch the top to encourage bushing out. "Pinch" means you rub out the new center growth to force two to three new breaks. There will be more flowers if you pinch. Bill Moynier says he never let's a leaf bud go un-pinched.
But be careful you don't accidentally pinch out a flower bud; they're often a different color, e.g., maroon. Also, they get fatter and don't elongate. When you're sure it's not a flower, pinch it out.
For a slow grower, it isn't worth pinching; they don't send out again. Sometimes even though you pinch back a branch, the branch will send up only a single shoot again. You don't usually prune mature growth. When a plant ages, it tends to break from the base.
You probably won't have much luck with plants in 1-gallon containers; the roots don't go down; they go out. The bottom of the can stays too wet. Use hanging plant baskets, which are wide and shallow.
Phytophthera (root rot): once the plant starts to wilt, it's history. Take a tip cutting, put it in water overnight and then strip and put into rooting medium. You might be able to salvage a new plant from the bound-to-die one.
Keep the ratio of planting medium to root size low. Vireyas like crowding. Once the roots fill the pot, move up slowly to the next pot size.
Let plants dry out between waterings. You don't have to soak the pot. You don't want a continuously happy medium for fungus, etc.
Fred Renich repots every year; Bill Moynier repots every three or four years. It's okay to beat the heck out of the root system to shake off old mix. They aren't bothered (except the young ones). Repot in the same container unless root-bound. You can trim the roots when potting up, if firmly balled.
Cuttings: usually cut, strip, dust in hormone powder and put into cutting bed. You might want to try putting vireya cuttings into a jar of water with some willow cuttings. A clean root is white; once it's brown, it's gone.
Sprinkle or mist in hot weather, in the early morning or late afternoon (not when the sun is hot).