Search found 416 matches

by david zlesak
Thu Jan 14, 2021 3:56 pm
Forum: Rose Hybridizers Association Forum
Topic: Koppen Geiger Climate
Replies: 2
Views: 113

Re: Koppen Geiger Climate

Hi Sarah! The American Rose Trials for Sustainability (trustedroses.org) uses this system too for regional awards. The combination of temperature and precipitation patterns seems to make it more useful than just the minimum coldest temperature like for the USDA Cold Hardiness zones https://www.ameri...
by david zlesak
Sat Jan 09, 2021 12:03 am
Forum: Rose Hybridizers Association Forum
Topic: Another virus that infects roses found
Replies: 2
Views: 93

Re: Another virus that infects roses found

Dimitre and Maher do such great work and it is nice they are mentoring others in these techniques. I'm grateful they continue to do virus discovery work with roses, especially when it is generally easier for them to secure money to characterize new viruses in other crops.
by david zlesak
Wed Jan 06, 2021 8:45 pm
Forum: Rose Hybridizers Association Forum
Topic: opinions on retaining a seedling
Replies: 2
Views: 114

Re: opinions on retaining a seedling

I doubt it too.... The resistance is dominant. Brite Eyes has only one copy of that dominant allele across its 4 sets of chromosomes and just a portion of its seedlings inherit it. There is a race of black spot that can overcome Brite Eyes, but most all the races in our collection don't. If your BE ...
by david zlesak
Tue Dec 29, 2020 11:37 pm
Forum: Rose Hybridizers Association Forum
Topic: Can Somebody Explain 'Replicative Fading'?
Replies: 9
Views: 326

Re: Can Somebody Explain 'Replicative Fading'?

That's a great question... I assume they mean that through many years and propagation cycles plants begin to show "drift" / decline in terms of performance, especially if careful attention isn't given to propagating from just the most representative plants. For part of my Ph.D. I studied performance...
by david zlesak
Sun Dec 27, 2020 6:06 pm
Forum: Rose Hybridizers Association Forum
Topic: Rooted Cuttings Failure Question?
Replies: 30
Views: 1247

Re: Rooted Cuttings Failure Question?

Hi Philip, I ordered the liquid form of Bti from a Florida pond supply company (123Ponds; I think it was a 6 or 8 ounce bottle, I have to check- it was about $20 I think). Their main customers are using it for mosquito control in ponds and that is what is on the label when it came, but the website s...
by david zlesak
Fri Dec 25, 2020 5:35 pm
Forum: Rose Hybridizers Association Forum
Topic: rugosa x glauca
Replies: 6
Views: 544

Re: rugosa x glauca

Hi Duane!! I'm excited for you to follow these. Hopefully you can just put them all into larger pots and prune them as needed to keep them all in their space allotted until spring. It would be a shame if they vary for health and other traits and you miss the opportunity to discover those things at t...
by david zlesak
Tue Dec 22, 2020 11:42 am
Forum: Rose Hybridizers Association Forum
Topic: Rooted Cuttings Failure Question?
Replies: 30
Views: 1247

Re: Rooted Cuttings Failure Question?

That is wonderful rikuhelin1!! I'm so glad they are taking. Thank you so much again Stefan!! I got Bacillus thuringiensis subsp./var. israelensis and it is working. After the first application it really knocked the fungus gnats down and a couple weeks after now I mixed some more and treated again. I...
by david zlesak
Thu Dec 17, 2020 3:06 pm
Forum: Rose Hybridizers Association Forum
Topic: Scandinavian Import ID Challenge - Needle in Haystack Quest?
Replies: 22
Views: 2533

Re: Scandinavian Import ID Challenge - Needle in Haystack Quest?

Hmmmm It looks like the rose I've seen in the past at the MN Landscape Arboretum labeled 'Kakwa', a spin hybrid. The wide hypanthium under the sepals suggests Spin hybrid to me. At the MNLA 'Kakwa' got about chest high and 6-8' wide and died back somewhat each winter.
by david zlesak
Sun Dec 06, 2020 11:41 pm
Forum: Rose Hybridizers Association Forum
Topic: Rust
Replies: 6
Views: 503

Re: Rust

I added a link to a paper by Dr. Kermani et al., 2009 characterizing various species of fungi causing rust in roses. This seems like a pretty diverse group of pathogens for having such a variation of species causing similar symptoms and growers calling it all by the same disease name. http://www.glo...
by david zlesak
Sat Dec 05, 2020 11:29 pm
Forum: Rose Hybridizers Association Forum
Topic: Rooted Cuttings Failure Question?
Replies: 30
Views: 1247

Re: Rooted Cuttings Failure Question?

Wow, thank you sooo much Stefan for pointing out Bacillus thuringiensis and this strain labeled for fungus gnats. I'm super excited to get some and think it'll be less expensive and have a longer residual than hydrogen peroxide. It becomes difficult for me with lots of seedling trays of small cells ...
by david zlesak
Fri Dec 04, 2020 7:32 pm
Forum: Rose Hybridizers Association Forum
Topic: Rooted Cuttings Failure Question?
Replies: 30
Views: 1247

Re: Rooted Cuttings Failure Question?

One thing I've tried last year that has really helped with fungus gnats with seedlings is hydrogen peroxide. I've mixed it about 1 part 3% from pharmacy to a few parts water. The media bubbles and kills the larvae and hasn't seemed to impact roots of rose seedlings. It takes a few applications since...
by david zlesak
Fri Dec 04, 2020 3:58 pm
Forum: Rose Hybridizers Association Forum
Topic: Rooted Cuttings Failure Question?
Replies: 30
Views: 1247

Re: Rooted Cuttings Failure Question?

I notice that too.... I wonder too if I have them too wet. I suspect in some instances the blackening may be due to one of the root rot organisms getting in and disrupting the vascular system and connection between the top of the cutting and roots. Sometimes when I have cuttings I'm potting up and t...
by david zlesak
Wed Dec 02, 2020 11:50 am
Forum: Rose Hybridizers Association Forum
Topic: i.d. this rugosa hybrid???
Replies: 12
Views: 591

Re: i.d. this rugosa hybrid???

This is just a guess, but 'David Thompson' from Svejda. It was popular "a long time ago" in relative terms (~20 years ago) and routinely sold for awhile with her other wonderful Explorer roses. I think it is more petite in terms of its leaf size than the other commonly sold double magenta rugosas.
by david zlesak
Tue Nov 17, 2020 11:53 am
Forum: Rose Hybridizers Association Forum
Topic: Unexpected precocious germination
Replies: 1
Views: 215

Unexpected precocious germination

This past weekend I went through accumulated baggies of rose seed in moist peat at room temp. to take inventory and then get them into the refrigerator for their cold treatment. Most have been sitting for between a month and two months now for a warm stratification treatment before cold. There typic...
by david zlesak
Wed Oct 28, 2020 6:49 pm
Forum: Rose Hybridizers Association Forum
Topic: Germinating Alba seeds...question...
Replies: 8
Views: 570

Re: Germinating Alba seeds...question...

My suspicion is that they'd benefit from warm stratification first (couple months in moist substrate at room temperature or so) before their cold stratification period, like other Caninae relatives. I had much delayed germination going straight to cold where they then needed to go through the next s...
by david zlesak
Sun Oct 25, 2020 1:54 pm
Forum: Rose Hybridizers Association Forum
Topic: Julie Overom's Cherry Frost is the big winner of the Biltmore Trials this year!!!
Replies: 8
Views: 542

Julie Overom's Cherry Frost is the big winner of the Biltmore Trials this year!!!

Congratulations Julie!!! Cherry FrostTM ('Overredclimb') is an incredible rose. It is also an A.R.T.S.(R) award winner for multiple regions for 2021 as well, which is a national trial with several locations across the country!! I love it for its health, vigor, and abundant clusters of gorgeous doubl...
by david zlesak
Sun Oct 25, 2020 1:38 pm
Forum: Rose Hybridizers Association Forum
Topic: Extra plants to share of a R. wichurana seedling
Replies: 9
Views: 1195

Re: Extra plants to share of a R. wichurana seedling

Great advice Kim!! I just have had this one sprawling and it is crawling over its neighbors :0)
by david zlesak
Sun Oct 04, 2020 2:12 pm
Forum: Rose Hybridizers Association Forum
Topic: First Report of Phyllocoptes fructiphilus Keifer (Eriophyidae), the Vector of the Rose Rosette Virus, in Florida, USA
Replies: 3
Views: 413

Re: First Report of Phyllocoptes fructiphilus Keifer (Eriophyidae), the Vector of the Rose Rosette Virus, in Florida, US

From visits with Mark Windham, it sounds like he has a graduate student looking at what may be different. From my understanding, it sounded like the mite was less prolific South of a certain line in Texas and further East and that may be due to a combination of heat and humidity and possible mite pa...
by david zlesak
Fri Sep 25, 2020 1:21 pm
Forum: Rose Hybridizers Association Forum
Topic: Sweet Spirit
Replies: 15
Views: 1481

Re: Sweet Spirit

I really like Orchid Romance, but it doesn't seem to set hips for me and it has been hard to get pollen from it with the blooms being so double. Sweet Spirit was for sale mid summer in the Home Depots here in 2 gallon pots. I wish I would have bought one now. It was really hot and they weren't being...
by david zlesak
Wed Sep 23, 2020 2:35 pm
Forum: Rose Hybridizers Association Forum
Topic: New black spot article out today
Replies: 3
Views: 486

New black spot article out today

Hi Everyone, I'm so excited this article is finally out. With the pandemic and lab restrictions I'm glad we obtained the special permissions to follow through on the additional rounds of inoculations we had ongoing in March to confirm the reactions at the same point in time on the group of roses tha...