Keeping the Bloom on Your Roses

I've been noticing that the roses in West Seattle gardens are particularly beautiful this year. This is worth noting because the climate in the Pacific Northwest is not the best for growing roses. Roses love sun and we don't get a lot of it. Our cool, damp days are better suited to the growth of fungal diseases, like black spot, that love to build colonies on the leaves of our rose plants. 

(Some roses more suited to our climate than others. If you want to know more about them, I recommend Christine Allen's book, "Roses for the Pacific Northwest.")

So why are our roses looking so good this year? I suspect that it has to do with the extra rainfall we've had this year. Our usual rainfall pattern is that we have adequate rain to keep gardens looking lush through the month of May. In June, we often have a lot of cloudy days, but not very much rain. Gardeners are fooled by the cloudiness into thinking the garden is getting enough water, when that isn't necessarily the case. Particularly with roses, which are greedy on all fronts: they want lots of water, sun, and nutrients. 

So far this year, we have had three times the usual amount of rainfall for the month of June. This has had the effect of extending bloom time for lots of spring flowering shrubs and perennials. Roses, most of which are at the beginning of their bloom season, are getting off to a healthy, well-watered start this year. If you want to keep the bloom on your roses throughout the summer, I suggest that you consider following up with a good fertilizing routine. Ideally, that routine would have started months ago, but whatever you do to feed your roses from here on out will be rewarded.

Here is a 4-Step feeding program for roses that was given to me years ago by a rosarian with a passion for both beautiful roses and keeping hazardous chemical use to a minimum. He has long since sold his nursery and moved out of the area. Thanks, Robert, wherever you are! 

If you are fertilizing your plants for the first time in June, skip step one and continue from there.

1. In February, March or April, apply 1 cup of superphosphate to each rose in your garden. Superphosphate works better than bone meal because it breaks down faster. It builds strong root systems and improves the rose's ability to flower repeatedly over the summer. It also costs less. Use it only once a year.
2. Apply 1 cup of alfalfa meal of 2 cups of alfalfa pellets to each rose in March or April. Some rosarians repeat this application in June. Alfalfa releases nitrogen slowly and releases an enzyme that dramatically increases the rose's feeder root system. This means that the plant can make better use of available nutrients in the soil, as well as the fertilizers you give it.
3. Starting in April, as the soil begins to warm, apply 1/2 cup of granular 16-16-16 fertilizer, and re-apply every 4-6 weeks. Your last application should be in August. (As with all granular fertilizers, water well after application unless you have adequate rainfall to dissolve them.) This step is the core of your feeding program.
4. Apply Epsom salts (magnesium sulphate) to your roses to stimulate new, larger canes and to enhance flower color. Use 3/8 to 1/2 cup per rose in May or June. Magnesium sulphate, combined with a complete feeding program, does a good job of rejuvenating old, tired roses. 

Along with a good feeding program, be sure that your roses get plenty of water during dry spells. They aren't as thirsty as lawns, but still - they aren't drought tolerant. Also, roses need lots of sun. There are a few, rare cultivars that will grow in shade, but most will be leggy, buggy and fail to bloom unless they are in full sun.

Be aware that even under the best circumstances, there are some rose varieties that are hopelessly susceptible to problems. If you have them in your garden, you might be better off replacing them with hardier cultivars. Ask at West Seattle Nursery for suggestions. There are lots to choose from. Enjoy!

Do you need a Horticultural House Call? For more information or to make an appointment, please email me. 

Puget Ridge Garden Center

This spring, I had the pleasure of "ghost blogging" for the Puget Ridge Garden Center at my alma mater, South Seattle Community College. This retail nursery/teaching facility is part of the Landscape Horticulture complex, completed just a few years ago, which includes the garden center, a greenhouse, cold frame building, head house, lath house and classrooms. This complex is a far cry from the dilapidated, 20-year-old, "temporary" classrooms that were in use when I was a student. After years of promises that construction would start "next fall," until fall came, and then "we'll break ground in the spring," and then more promises the following fall, it makes me happy to see this facility finally completed.

I've enjoyed visiting the college weekly, seeing what is new and taking photos. It has reminded me of how much I enjoyed plant ID, landscape design, horticulture science and propagation classes. It was one of the great joys of my life to be so immersed in the study of something I loved so much. Even though I stepped away from design and consulting work in recent years,  due to health issues, I never lost my passion for it. Spending time at the college these past months has reminded me of that, and it has been part of the reason I am returning to the business.

But now the quarter is drawing to an end and the garden center will be closing until fall. Will I will resume my "ghost" blogging position then? I don't know. What I do know is that there are some great deals to be had on plants this week and next. There's some gorgeous plant material there, with prices at or near wholesale. While you're there, take a look around. Maybe you, too, will be inspired to sign up for a class. Check out the Puget Ridge Garden Center blog for more details on dates and hours open.