Good afternoon,
I am a self confessed novice who could do with some expert opinion!
I live in South London on a busy A road and have a 5th floor glazed balcony which faces North west and thus gets the summer afternoon sun, which, naturally, I adore but anything green (so far- Japanese maple, bay tree, various flowers) that I've put out there has perished. Symptoms include
-Leaves of a bay go brown from the outside in. The whole plant doesn't seem to grow.
-Rosemary dries out entirely, leaves go brown and the plan refuses to grow.
-Japanese maple - leaves dry and wither (despite careful watering) and fall off entirely.
-Lilly surprising grows very well, albeit only emerges periodically and disappears entirely before the hotest of the summer sun.
Have always presumed that the combination of the hot summer sun, the glazed balcony and the poor quality air had lead to their demise, but cannot be certain.
The purpose of my query is as follows; what do you think will survive my balcony? Indeed, can anything? Do you think the above conditions are likely to be a key contributor to their early death?
Many, many thanks in advance,
Andy and Rachel
-
applestar
- Mod
- Posts: 30541
- Joined: Thu May 01, 2008 7:21 pm
- Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)
Northwest setting sun can get terribly hot in the summer. I'm thinking in London, you would get a longer day than here... maybe the sun sets further north as well? -- how many hours of direct sun? Also glazed -- no ventilation? I think it would best to keep a max/min thermometer in there to monitor the temperature. Too hot can definitely be an issue.
The hours of direct sun is critical.
I'm thinking rosemary should be able to manage if you get sufficient hours of sun and you take care not to let the soil dry out. You need to watch out for red spider mites.
But you have mentioned perennials and trees -- how they are being cared for during the rest of the year would contribute to how well they do in these conditions in the summer. If they don't get as much sun... not enough sun.... and then whether you are acclimating to the balcony conditions after keeping them elsewhere or they spend year-round on the balcony.
Need more details on your growing conditions for the perennials but maybe herbs like thyme and oregano, tarragon, marjoram, chives, ..maybe strawberries, ....
For annual flowers, I could see heat and drought tolerant ones -- celosia, zinnia, marigold, nasturtium, balsam, salvia, wax begonia, petunia....
Trees -- I could see citrus growing here, sweet bay should have worked but are prone to pests like scale insects,
Also annual Herbs like basil, perilla...
Maybe succulents, aloe, etc.?
I think you should start with easier container plants than most trees and slow-growing Japanese maple has not been one of them for me. Oh! How about pomegranate? I started some from seeds and they are practically unkillable.
You could get dwarf varieties that would bloom and fruit. Oh, oh, and edible figs are pretty easy too. 
The hours of direct sun is critical.
I'm thinking rosemary should be able to manage if you get sufficient hours of sun and you take care not to let the soil dry out. You need to watch out for red spider mites.
But you have mentioned perennials and trees -- how they are being cared for during the rest of the year would contribute to how well they do in these conditions in the summer. If they don't get as much sun... not enough sun.... and then whether you are acclimating to the balcony conditions after keeping them elsewhere or they spend year-round on the balcony.
Need more details on your growing conditions for the perennials but maybe herbs like thyme and oregano, tarragon, marjoram, chives, ..maybe strawberries, ....
For annual flowers, I could see heat and drought tolerant ones -- celosia, zinnia, marigold, nasturtium, balsam, salvia, wax begonia, petunia....
Trees -- I could see citrus growing here, sweet bay should have worked but are prone to pests like scale insects,
Also annual Herbs like basil, perilla...
Maybe succulents, aloe, etc.?
I think you should start with easier container plants than most trees and slow-growing Japanese maple has not been one of them for me. Oh! How about pomegranate? I started some from seeds and they are practically unkillable.
You could get dwarf varieties that would bloom and fruit. Oh, oh, and edible figs are pretty easy too. It sounds like they are burning under your glazed balcony in summer. You may need to have some kind of shade netting or screen for the plants so they don't get microwaved in summer. The ones that are dry, I am taking are probably in too small a pot, you are not watering enough in summer, or it gets windy where you are and that is drying out the plants, or you have saucers under the pots and the roots have rotted which shows the same effects as not getting enough water.
Bay leaves and rosemary can handle the sun but although they don't like to be sitting in water which will kill them, they do need a fast draining soil, regular water, and no saucer.
Japanese maples are annuals here, they cannot handle heat.
Bay leaves and rosemary can handle the sun but although they don't like to be sitting in water which will kill them, they do need a fast draining soil, regular water, and no saucer.
Japanese maples are annuals here, they cannot handle heat.