Search found 422 matches

by Larry Davis
Thu Jun 25, 2020 11:28 pm
Forum: Rose Hybridizers Association Forum
Topic: Yellowing of rose leaves.
Replies: 7
Views: 204

Re: Yellowing of rose leaves.

Cement is mostly calcium silicate plus a little calcium sulfate so that concrete is most likely the same except for sand and gravel (I looked up Portland cement on-line). Magnesium sulfate has the oxidized form of sulfur, sulfate, so if you take away the magnesium it is sulfuric acid. The final pH o...
by Larry Davis
Sat Jun 06, 2020 9:59 pm
Forum: Rose Hybridizers Association Forum
Topic: 'Commander Gillette' X "3/4 Native"
Replies: 32
Views: 1876

Re: 'Commander Gillette' X "3/4 Native"

Add mildew to some setigera. Those from David Z, at the U of MN arboretum location didn't mildew, but my line which derived from one at K-State, acquired decades ago, mildewed itself maybe to death after overwintering as rooted cuttings while the others stayed clean. I guess the same will be true of...
by Larry Davis
Sat May 30, 2020 10:16 pm
Forum: Rose Hybridizers Association Forum
Topic: first roses of the year
Replies: 29
Views: 1533

Re: first roses of the year-mini orange

Teh enter on that one is very "muddled". I see only about half a dozen definite stigmas. So it could be nearly or quite sterile as a mother. On teh otehr hand there are lots of anthers all round. If you just leave this cut rose on a sheet of waxed paper, or on a white plate, you should be able to se...
by Larry Davis
Mon May 18, 2020 9:59 pm
Forum: Rose Hybridizers Association Forum
Topic: Yellow blend rugosa hybrid
Replies: 22
Views: 1039

Re: Yellow blend rugosa hybrid

The rose I referred to above is still holding its petals after quite a few days. The cross was Brite Eyes x Above and Beyond. It is one of the few juvenile bloomers I got out of well over 100 seedlings. I think these are real crosses because so far as I can see, Brite Eyes OP gives many more repeat ...
by Larry Davis
Mon May 18, 2020 5:55 pm
Forum: Rose Hybridizers Association Forum
Topic: Yellow blend rugosa hybrid
Replies: 22
Views: 1039

Re: Yellow blend rugosa hybrid

That fade is very interesting. I would have expected that the yellow would go and the pink would hold. That's what happens to almost every orange, apricot, gold flower that I breed. Does this stay green or drop its petals cleanly? If this one doesn't get a lot of B.S. or mildew, I'd love to try usin...
by Larry Davis
Sat May 16, 2020 10:35 pm
Forum: Rose Hybridizers Association Forum
Topic: Yellow blend rugosa hybrid
Replies: 22
Views: 1039

Re: Yellow blend rugosa hybrid

Very good result. My problem with 13-1 is that it is not reliably winter-hardy out in the elements in our winters which rarely dip below zero. I had hoped it would do better with one parent being Orange Surprise which is ([Carefree Beauty x Rise N Shine a.k.a Pink single] x [Carefree copper= Carefre...
by Larry Davis
Mon May 11, 2020 9:44 pm
Forum: Rose Hybridizers Association Forum
Topic: using vinegar to lower soil pH
Replies: 3
Views: 362

Re: using vinegar to lower soil pH

Citrate lasts a little longer than acetate but not much. It was tried several decades ago to help plant remove heavy metals from soils, testing the theory that plant that make citric acid and excrete it into the soil are able to take up the unwanted metal better.But what happened was that there were...
by Larry Davis
Sun May 10, 2020 10:58 pm
Forum: Rose Hybridizers Association Forum
Topic: using vinegar to lower soil pH
Replies: 3
Views: 362

Re: using vinegar to lower soil pH

All I can say is that acetic acid is a perfect carbon substrate for many bacteria. So don't expect it to hang round in the soil more than a few weeks. I've grown blueberries for decades in an area with pH 8 soil. First I used a bale of peat for each plant. Later I added pounds of ferrous sulfate. Th...
by Larry Davis
Sat Mar 14, 2020 11:39 am
Forum: Rose Hybridizers Association Forum
Topic: Strat Question
Replies: 6
Views: 283

Re: Strat Question

Again, I don't think there is any clear answer. If I had a hundred seeds, I'd plant half after cleaning them out of the hips, and put the other half into vermiculite moistened with calcium nitrate and keep in the fridge until they sprout. Of course that will/might cost you a couple months of potenti...
by Larry Davis
Fri Mar 13, 2020 10:35 pm
Forum: Rose Hybridizers Association Forum
Topic: Strat Question
Replies: 6
Views: 283

Re: Strat Question

Not a silly question, just hard to answer. Generally it seems that simply storing fresh hips in a refrigerator is not enough to make them think they have been stratified. But outdoors they are not at a constant 4 C. Depending where you live, they may have gone through multiple cycles of freeze and t...
by Larry Davis
Fri Mar 13, 2020 7:32 pm
Forum: Rose Hybridizers Association Forum
Topic: Unique black spot resistance gene from 'George Vancouver' is better characterized
Replies: 19
Views: 963

Re: Unique black spot resistance gene from 'George Vancouver' is better characterized

Really good news. I wonder where RKO got the resistance. Not apparent from its short-range family tree I suppose? The notes I have on that say RKO is the same parentage as (Radsweet) Alaska. and a half-sib to Brite Eyes. Namely Radtee x Radral. But Radral (Carefree Celebration) is Radorg x Rader whi...
by Larry Davis
Mon Mar 09, 2020 9:25 pm
Forum: Rose Hybridizers Association Forum
Topic: Germination of crosses I'm excited about
Replies: 13
Views: 815

Re: Germination of crosses I'm excited about

Finally have flowers from some crosses with Above and Beyond, and my #1100 (similar growth habit but descended from R foetida bicolor). This at least shows that the recessive reblooming trait will pop up at a decent frequency. No count yet to get a % but it is several % at least. Best news is that I...
by Larry Davis
Mon Mar 09, 2020 9:09 pm
Forum: Rose Hybridizers Association Forum
Topic: maximum germination temperature
Replies: 6
Views: 296

Re: maximum germination temperature

What you did is exactly how HSP are induced in crop plants and model plants like arabidopsis. Generally, if the stress is removed soon the plant recovers. In fact it become resistant to an even higher temp, up to some limit. The upper limit even after preparation by inducing HSP is quite species dep...
by Larry Davis
Sun Mar 08, 2020 7:14 pm
Forum: Rose Hybridizers Association Forum
Topic: maximum germination temperature
Replies: 6
Views: 296

Re: maximum germination temperature

Do I actually "know" the magic temp? No, but Semeniuk and Stewart discussed optima for stratification and germination, and the tendency for seeds to go back into dormancy above certain temps, if not fully after-ripened. I just looked back at my review (on this website) and find that they used 29.3 C...
by Larry Davis
Sun Feb 23, 2020 2:56 pm
Forum: Rose Hybridizers Association Forum
Topic: Coutts #4
Replies: 11
Views: 788

Re: Coutts #4

Carefree Sunshine (probably climbing sport) is a far better bush than SKO in my experience. And I have yet to keep anything from SKO selfs, despite planting a couple hundred. Paler than pale flowers and single only. CS on Silver Moon has produced a couple really nice flowering bushes but again extre...
by Larry Davis
Sat Feb 22, 2020 10:02 pm
Forum: Rose Hybridizers Association Forum
Topic: RHA Newsletter coming your way!
Replies: 4
Views: 454

Re: RHA Newsletter coming your way!

Are batches of newsletters still on their way? Or am I non-renewed? @ weeks and counting.
by Larry Davis
Mon Feb 17, 2020 10:15 pm
Forum: Rose Hybridizers Association Forum
Topic: Coutts #4
Replies: 11
Views: 788

Re: Coutts #4

Plazbo says "I still think sifting through the tiny % of rebloomers in the f2 of (modern x species) x self/sib is more interesting and to turn up useful breeders than jumping straight to another garden rose and further diluting the species compliment before having a useful breeder. I mean whats the ...
by Larry Davis
Sun Feb 16, 2020 9:58 pm
Forum: Rose Hybridizers Association Forum
Topic: Coutts #4
Replies: 11
Views: 788

Re: Coutts #4

Thank you Don for quoting that article. I probably read it decades ago when looking up all the articles I could find on hardy rose breeding, in all the rose annuals back to 1918, but had forgotten entirely some parts (90% or so) of it. But it raises a serious question for me now. By what criteria wi...
by Larry Davis
Mon Feb 10, 2020 10:39 pm
Forum: Rose Hybridizers Association Forum
Topic: Homemade rooting hormones
Replies: 6
Views: 364

Re: Homemade rooting hormones

Thank you. I was thinking the opposite because traditional outdoor winter planting of hardwood cuttings occurs in something like a coldframe. I've tried the burrito method in my basement which is rather cool in winter, and in a cold greenhouse. Neither worked. Next time I'll go for a warm lab. BTW, ...
by Larry Davis
Mon Feb 10, 2020 7:15 pm
Forum: Rose Hybridizers Association Forum
Topic: Homemade rooting hormones
Replies: 6
Views: 364

Re: Homemade rooting hormones

Apple, or banana peel. Back around 1980 I deliberately added low level ethylene to cuttings and got callousing at both ends. But for some CV the leaves dropped off and roots refused to form. I get callous in the burrito method but have really bad luck making the transition to rooting. Maybe I need t...