Seedling questions

For the most part, my seedlings are b/w 4 and 8 true leaves…

Firstly, is it typical to have a variety of thorniness on O.P. species roses when seedling are immature, and does that typically change as they grow? I have a bunch of (presumably) woodsii (arizonica or fendlerii) some of which have a good deal more bristles than others, and some are virtually smooth. I’m assuming this is cultural at this juncture as they are all crammed into one pot. Should I not count my thorns before they hatch?

When growing seedlings from a thornless parent (setigera serena) how soon can one surmise thornlessness or otherwise? Do tiny prickly hairs typically portend thorns when the plant is older?

At what stage does one stop worrying about damping off?

What are the best, most balanced fertilizers, in folks’ opinions? (I’m using mostly Miracle Grow All Purpose 24-8-16 – though I have used a spot of calcium/magnesium nitrate with a touch of bloom builder type – but I do have some leaves that look slightly chlorotic – mostly in my over-packed pot, mind you, so I assume it ain’t the formulation so much as the competition. Not ready to cull yet, but I think it’s high time I divide and repot.)

Finally, what is the safest way to address aphids on tiny seedlings? I’ve just been squashing them b/w my fingers up to this point, and that seems adequate, but wonder what other do.


[quote] Should I not count my thorns before they hatch?[/quote] I sure would not. With woodsii, it might be safe to say that they will probably get more bristly as they mature.

[quote]When growing seedlings from a thornless parent (setigera serena) how soon can one surmise thornlessness or otherwise?[/quote] Maybe never, except maybe in cases like setigera and some banksiae where thornlessness is the norm. These certainly do seem to be varietals that are consistently less thorny than others. But not always. I have a friend who has the thorniest group of Iceberg that I have experienced-I helped her prune them and emerged quite bloody. I have seen those vary from almost thorn free to quite thorny. And then there is the freak stem that sometimes appears after many yrs on either end of the spectrum with the opposite of the description used in catalogues.
Damping off? have never experienced it.
Ferts? My local pot grower would laugh with scorn at the mention of Miracle Gro. (He does not believe that I buy the stuff I buy for roses. Who has that many roses?) But any organic fert for most flowering (tomato ferts work well) plants will suffice. I like the FoxFarm line to keep this a simle answer. It comes in both a liquid and an organic dry formula. I tend to mix my own but that can lead to unintentional overfertilizing and frying batches of young plants. It has happened.
Aphids? Cultivate a very friendly relationship with small finches, bush tits, fly catchers, etc. And do not allow Coopers Hawks to nest in the vicinity.

I agree with the bird answer for aphids, etc. Santa Maria has birds up the wazoo and aphids, etc. are not a problem. Spider mites? In droves, but few aphids. Organics are nice, but if you have a dog, and it has access to where you grow your roses, forget them. ALL organic anything are “dog treats”. Sluggo and all other “pet safe” snail and slug baits are also “dog treats”. We can’t buy the non pet safe products here now, so I have to carefully hide the baits where the vermin can’t get at it. I use Miracle Gro All Purpose liquid in the hose end sprayer for everything, hibiscus, roses, tomatoes, orchids, perennials, all of it and they all grow and flower. If you’re concerned it’s too strong, you can pry off the bottle top of the refills, pour half into an already used bottle and fill them both up with water. Snap the top back on, replace the lid and shake well, then remove the lid and screw it into the hose end sprayer. You’re now using half strength and can use it twice as frequently.

The thorny Iceberg indicates the plant is attempting to throw climbing canes. The thornier the cane, the more closely it is to the climbing sport. It happens all the time. Mlle Cecile Brunner does the same thing.

Thank-you. Did not know about the climbing canes and thorns, but makes perfect sense. This would also account for the fact that these particular roses, sort of a hedge below a large picture window, also try to reach 6-7’ despite all efforts to curb them. They face south, get plenty of sun, but always look like they are reaching for the sun! And the point of putting these in were: they bloom non stop (true), are easily kept to under 4’-5’ with a little pruning (not really), and they would not block the light (this has been a big problem!).

Back to Philips’ question about the chlorosis. I suspect that it may be caused by the high ph in the soil of the community pot. Or it could be caused by a lack of sulphur (which Miracle Gro does not add to their formula). If you are getting the formula with chelated iron, that might solve the chlorosis problem, but the ph may be still too high if you are still experiencing chlorosis in the young plants.