A journey to a no-spray rose garden by Sumera + tips for pests/diseases mgmt in Houston
I was most excited about this blog as I was thinking about interviewing someone who had experience and knowledge about pest and disease management for a long time. Sumera was the person that came to mind, but I was not sure how she would feel about it.
As we know, growing roses in our Houston, Texas climate almost seemed impossible as our climate is very humid and hot which makes a perfect environment for pests and diseases. Growing roses in Houston, Texas is challenging BUT totally possible.
Dream came true when Sumera kindly offered to share her knowledge and personal story with us. Her journey is very interesting as Sumera started out as a rose gardener who spent a great deal on educating herself on rose care, disease/pest prevention and management for our hot and humid Houston, adopted a spraying routine, then decided to go a completely opposite direction.....a no-spray garden!
**I want to make it clear that the intent for this post is NOT to judge or shame anyone for spraying or not spraying. Your garden is yours and I believe that everyone has a choice to do what's right for them. My goals are to share with you what's available, ask our rose friends who're willing to share their experience/results and create a safe space for us to respectfully exchange ideas/ways in doing things. It's up to you to decide what's best for you and your garden. Also, both Sumera and I are not professional rose growers nor rose experts. We are rose lovers and backyard gardeners sharing what works/doesn't work in our journey. Do your research prior to using any products and read label carefully.
Tat: How did you start your rose gardening?
Sumera: I started rose gardening in 2009, back in my parent’s garden. I used to search for seeds and plants online because I was a graduate student/worked full-time and hardly had time to go to nurseries.
Anyhow, I stumbled upon the David Austin roses website when I was searching up rose plants. It was love at first sight; I ordered 12-14 bare root roses and planted them in the backyard. I remember some of the names: Molineux, Winchester Cathedral, Mary rose, Queen of Sweden, L. D. Braithwaite etc. My dad sold that property when all of us married and moved.
When I bought my current property in 2018, I rekindled my love for roses and gardening because I now had a huge backyard space.
Tat: How many roses do you currently have? Where are you located (what the growing condition is like? Hot and humid? Clay soil and etc)?
Sumera: I have close to 90 roses currently, (I dare not do an exact count :D) with a few still waiting in pots.
I am located in the South of Houston area; our growing conditions are hot, humid, occasional frost in the winter as well as droughts during summer. Our soil is clay, with poor drainage.
I have never succeeded in growing roses in our native soil without any amendments. I always create raised beds with good quality compost to ensure the plants will have good drainage. It also eliminates the chance of flooding due to tropical storms or hurricanes.
Tat: Can you share about your spray routine back in the day (what products worked well for you, how did you use - this will help people who want to know how to manage diseases and pests with products)?
Sumera: I was using Bayer 3-in-1 based on David Austin’s recommendation for black spot and thrips when I first started growing roses. It worked some but wasn’t a perfect solution. Probably because the pests become resistant to Bayer. Keep in mind, I also did not use good quality fertilizers either. I used Vigoro rose food in addition to the chemical fertilizer already included in the Bayer product.
I had more time at this point in my life, I became committed to a spray routine once I planted at my current property in 2018. I joined the Houston Rose Society that summer and started emailing/calling local rosarians whenever I saw issues in my garden.
A rosarian guided me and I established a routine with different chemicals. I bought a 2 gallon sprayer can because I had a lot of roses. You can mix the listed products according to the label, and make sure to add a surfactant to help the spray stick to plant foliage.
I have listed below all the products that I used throughout the season. I also started using organic fertilizer and added a lot of good things to the soil. I purchased from Southwest Fertilizer, and Rosemania website.
Bonide All Seasons Horticultural oil (applied in the dormant season after pruning, never spray dormant oil when plants have foliage).
Daconil Fungicide - first fungicide in early spring when weather is still cold. (Do not use it when the temperature is above 80 degrees).
Once plants have foliage, spray bi-weekly:
Bonide Mancozeb fungicide (if black spot is already present, spray mancozeb by itself every week)
Propiconazole 14.3% (also known as Honor Guard or Banner Maxx) this can be sprayed alone if no black spot is present
Once flower buds have slight color:
Conserve (Spinosad concentrate for thrips control) this will kill thrips early on before it becomes an infestation.
If caterpillars are destroying foliage:
These products are sprayed in the evening or very early morning to avoid burning foliage. Cycling fungicides and pesticides is key to preventing resistance. You can cycle the spinosad with imidacloprid in your spray routine.
Many different chemical fungicides are available in the market, switch them frequently also. The flower buds only (not the whole plant) have to be sprayed with a product called acephate to ensure no discoloration/damage occurs due to thrips.
Unfortunately, we have a high insect pressure in our temperate climate and these sprays are the only way to achieve perfect blooms. I have seen numerous pictures posted of foliage burned due to spraying. In order to avoid this, roses should be deep watered before and after spray.
Tat: What year did you embark on a no-spray garden?
Sumera: Fall 2019 is when I stopped spraying.
Tat: You’re one of the gardeners who used to spray religiously, what was the turning point/circumstance that made you want to stop spraying?
I have to say that honestly I never really was happy with using these chemicals in my garden. I’m a biologist and understand that any chemical designed to kill insects or fungus is also detrimental to our health because we have the same type of cells in our body.
I was trying to achieve perfection in terms of foliage and blooms, I HAD to spray to achieve that. I also thought that roses would not survive if I didn’t use those chemicals since that’s what I was told by David Austin when I first started.
I was extremely burned out from all the constant spraying and removing black spot leaves. I always felt like it was one thing or another.
For example, I would get on top of black spot and thrips, but then I would see spider mites on literally every single rose. Which obviously was a result of the insecticides I sprayed.
The organic fertilizers were not providing much benefit because of all the chemicals I sprayed with. I decided to not spray and see what happens.
Tat: Share with us the state of your roses during the first few months after you stopped using fungicide/insecticide or any other preventative methods.
Sumera: To my surprise, nothing extreme happened. My roses lost their foliage, and some roses looked ugly due to thrips. Some plants had some black spot but others were actually okay.
After the winter, I pruned and just used the dormant oil. No fungicides or insecticides were used all growing season. I grew vegetables alongside my roses in the spring of 2020, since we were all at home during the lockdown.
No roses died, in fact a lot of my roses stopped getting black spot entirely because I used organic fertilizer plus compost and kelp meal. I no longer had a strict schedule I needed to follow. I felt like I was okay with some ugly foliage and flowers as long as I did not have to spray those chemicals.
Tat: How do you deal with pests and diseases in your no-spray garden?
Sumera: Spring pruning/clean-up is extremely important for lowering the pests/diseases all season. If you skip this work, you will be battling a lot of issues in the heat of the summer.
Insects from the previous season will have laid their eggs on the foliage and you will see a very large population from early spring. I prune hard and remove all foliage, I also clean all weeds in the flowerbeds and try to mulch as soon as I can. You can prune lightly for baby plants but definitely remove all foliage.
I remove all blooms and top foliage whenever I see thrips damage. I am not bothered by losing blooms because I like to control the population of thrips. I follow by feeding my plants. This is always helpful because my next round of blooms are beautiful.
I use a lot of things for the health of the soil, alfalfa meal, kelp meal, organic slow release fertilizer as well as occasional banana peels/coffee grounds. Healthy soil means healthier plants that build immunity to fungus over time.
I release beneficial insects like green lacewings and minute pirate bugs during the season. I try to mix in flowers to attract pollinators alongside the roses. I also have a water fountain in my garden which provides water for birds and insects.
Finally, the most overlooked aspect of gardening in our area is how essential water is. I hand watered for 3 years, my roses always lost their foliage in the summer months. Ever since I had automatic irrigation installed, I have seen a huge difference! My roses had green healthy leaves all summer last year, no roses died and even though I didn’t fertilize in the summer I still had flowers.
Tat: What differences do you notice with spraying vs not spraying?
Sumera: Some roses are not very healthy, and will not perform well, for example, peace rose, blue girl. I suggest doing your research in terms of which roses perform the best in our area.
Most newly planted roses will experience some black spot, but they will become stronger over time and you will see less fungal issues as they mature. Light colored roses will definitely have brown edges due to thrips, some may not even flower. While some will still look beautiful despite insect damage.
This is normal for our area and I hope we can set our expectations accordingly. Own root roses tend to be more healthier in my garden compared to grafted.
Tat: What are some of the roses that perform really well in your no-spray garden?
Sumera: I love Munstead Wood, because it is not bothered by insects at all. It is as close to a knockout rose as you can get in terms of low maintenance. Thrips do not disfigure it, and I have not seen black spot on it since the first two years. Abraham Darby is my favorite for the size of the blooms, and does really well in my garden.
Crown Princess Margareta is extremely vigorous here, will cover a fence fast & provide beautiful cupped blooms. Princess Charlene De Monaco, Poseidon, Anastasia are some of the best performing roses in my garden. I still have a long list that I love and cherish, and I can share it with pictures later. My garden is beautiful as a no spray garden :)
Thank you so much Sumera for taking your time to share your journey, experience and knowledge with us. I hope you find this post helpful when it comes to pest/disease management, what products to consider as well as tips for the no-spray methods if you are thinking about going that route.
Please thank our rose friend Sumera by sending a message via FB or following her on Instagram at @sumera.suleman
If you have any questions for me or want me to blog on specific topics, let me know in the comment section.
Enjoy your rose gardening,