Hi, I've just bought a small Costus barbatus and would like some advice about growing conditions. Everything I've read has said that they're easy to grow and love sunny positions. I garden zone 11 conditions -hot dry summers (max to 45C), moderate winters (no frost). I grow a lot of tropical plants and have a fairly shady garden and would like to know how much shade these plants can grow in and still thrive. I'd rather plant it in the garden than have it in a pot. Thanks, bertoli
Hey Bertoli, These plants do best with good light. They tend to stretch if planted in heavy shade. Avoid heat of the day sun as they will burn. Even though they are tropical plants gingers do not like to be in wet spots. That being said they don't like to dry out, best finding a well drained position where you can water regularly but not drown the plant. Hold back water in winter, although they don't go into full dormancy as with other gingers they do slow down a bit. Costus are pretty easy to propagate in mid spring from cuttings (just cut 10cm off tops and plant).
Thanks Chungi V I bought a tiny cutting from Tesselaar's catalogue as I hadn't seen them here. Do they grow in the same conditions as Alpinia? I grow a lot of Alpinia zerumbet syn A. speciosa variegata and another Alpinia sp (i've forgotten the name). The zerumbet/speciosa is easily managed whereas the other one grows like a weed with thick matting rhizomes and I always have to ruthlessly dig out clumps and cut it back. Is the Costus a vigorous grower? If so I'll need to be careful where i plant it. My basic garden soil is river sand so free draining is not a problem - once the water gets through the mulch etc :) ciao bertoli
It's definitely vigorous, though they form more of a shrubby mass rather than the likes of your Alpinia which grow into massive clumps, as you know. They can be pruned to maintain size a fair bit easier than some gingers. I prefer to grow the smaller Globba, Zingiber and Curcurma varieties I have about 6 or 7 that only get to 50cm in height and stay small. They do die back but only for about 2 months of the year. (If you like I can send you some seed after christmas from my Alpinia caerulea 'Redback': Native ginger with maroon undersides on foliage, it's just setting now. It's a bigger growing variety but very nice foliage contrast. I could probably add a couple other of little rhizomes in with them. I did a little selling on ebay a while back and had no problems with sending plant material to W.A.)
Hi Chungii V Thanks for the info - I know where to plant it now. I'd love some seed if you have any spare. The smaller plants sound wonderful - mine are 2.5 metre monsters (big for Perth but not your part of the world :) ) ciao bertoli
I'll get your details when they're ready. I just ordered another 200 Adenium seed so I won't have much room for anything else once they're up and going. Speaking of which have yours begun to show yet?
Hi, adenium seeds planted in a tray as you suggested. No sign of life yet but we've just had another cold rainy spell which is confusing everything. ciao bertoli
