Growing Roses in the Napa Valley
By Aileen Carroll for Van Winden’s Garden Center
There is perhaps no better time for roses in the Napa Valley than the month of May. All over town rose bushes are sporting their shiny new leaves and their first flush of flowers. Growing roses in our climate is not difficult at all, but can often become overly complicated if you source your advice online which may be aimed at an audience who lives in colder climes. Here is the information you need to know to grow great roses in the Napa Valley.
Be sure to mark your calendars for rose success. Roses follow a predictable schedule here in the Napa Valley. Bare root roses arrive at garden centers in late December and are sold as bare root until the end of January. March is when you want to give your existing roses their first dose of fertilizer for the year. New roses should remain in their black nursery containers until April 1st, which is when they have rooted out properly. Roses burst into full bloom in May and need to be deadheaded after their first blooms fade in order to encourage the maximum number of flowers in June and July. As long as we’re not in the middle of a heat wave, fertilize monthly with a balanced fertilizer up until late summer. December is the perfect time to prune your roses in the Napa Valley.
Van Winden Garden Center’s
Secret Rose Fertilizer Recipe
When you have at least three to six inches of new growth on your rose in March, mix 2 tablespoons E. B. Stone Sul Po Mag with 1 cup Alfalfa Meal and ½ cup Master Nursery Rose & Flower Food. Scratch this mix into the soil at the base of your rose and water it in well.
When shopping for a rose, consider inspecting the canes. Roses come in grades. You can find all grades of roses sold around the valley in the winter but only reputable locally-owned garden centers stock the highest quality roses these days. It is fair to be wary of cheaply priced roses that have few canes or are dipped in wax. Here’s how roses are graded:
#1 is the best of a variety. These have three or more healthy canes and a strong root system.
#1.5 roses have two or more thin canes and usually take longer to develop.
#2 roses have one or two small, thin canes and may require extra care to establish.
Iceberg is the most popular rose variety in the Napa Valley and for good reason! This variety is covered in romantic white blooms May through December as long as you deadhead it (cut off the spent blooms) every once in a while. Icebergs, like all roses, like to stay evenly moist at all times. In drought-conscious California, know that a three inch layer of mulch around the base of the plant can cut water needs back by up to 40%. Water all your rose varieties before 10am and avoid getting moisture on the foliage to lessen the chance of fungus spores taking hold.
Deadheading is necessary for a full summer of blooms. When looking at the flowering stem of a rose, you will notice that the leaves have fewer leaflets closer to the flowers. When snipping off the spent blooms, you want to make a sharp diagonal cut just above the highest leaf with the full number of leaflets. This will encourage the growth of a new flowering stem for a full season of rose flowers.
When breeding roses, it is difficult to have it all. Often rose breeders have to choose between scent, disease resistance, reblooming, and a long vase life. There are a few different classes of hybrid roses, some of which are more floriferous and some of which may have fewer flowers but work better for cutting and bringing inside. Hybrid tea roses are the classic choice for cut flowers as they mostly bloom singly on a long stem, while floribunda roses bloom in large clusters for an impressive show on the shrub.
Roses sometimes come in series with a range of bold colors but all sharing common traits. Veranda® roses have been bred to perform well in containers and still give you the look of English garden roses. The Eleganza® series is comprised of a wonderful collection of modern hybrid tea roses with a renowned disease resistance. Knock Out® roses are ‘self cleaning’ and continue to put on new buds even if they’re not deadheaded. The Drift® series are some of the smallest roses available and grow to be only a foot and half tall.
Our winters are not normally cold enough to trigger roses into a dormant state on their own so it is necessary to force them into dormancy by pruning them back and removing all their leaves by hand. This can be akin to ripping off a bandaid because here in the Napa Valley, roses are often still blooming and the foliage may look great in December if we’re having a mild winter! But please trust that giving your rose a fresh start for the new year is what is best for your plant. Leaves that look great in the winter will surely be covered in fungus by the following summer. Pruning roses can be intimidating but is necessary for the plant to be refreshed each year and keep disease at bay.
The staff at your local garden center are wonderful sources for information about pruning roses, choosing varieties for your garden, managing disease, and more! Sourcing your gardening information from professionals that have experience growing in your same locale will lead you in the right direction and set you up for gardening success. May is an ideal time to shop for roses since you can see the blooms and smell the scents for yourself. Enjoy this beautiful season and get out in your garden and have some fun.