America’s favorite flower, the rose, ranges in size from small miniatures (8 inches tall) to giant climbers that can reach 50 feet or more. Depending on the size, most rose varieties grow very rapidly. Tea roses reach mature height after only 3 to 4 years, even with yearly pruning. Some other species or climbing roses can live 50 years or more. Roses are heavy feeders and proper fertilization is important. Some shrub variety roses or old-fashioned roses can thrive with minimal nutrients, but modern rose varieties will benefit from regular feedings.
Applying fertilizer (feeding) to rose shrubs directs the quality and quantity of flowers produced. Because roses are heavy feeders, regular fertilizing is an important maintenance task to remember. Roses require three nutrients, (N-P-K) - nitrogen (N) for foliage growth, phosphorus (P) for root growth, and potassium (K) for flower formation. Roses also benefit from iron, calcium, and magnesium.
Mature rose shrubs benefit from regular feeding, while newly planted roses may be sensitive to fertilizer. For newly planted roses, a light application of liquid fertilizer will help to develop roots and establish the plant.
How to Fertilize Roses
Roses grow best in well-drained soil with a pH level of 6.0-6.5. Roses prefer neutral to slightly acidic soil. How much and how often you need to fertilize your shrub roses depends on the soil in your garden. Clay and loam soils hold nutrients well which means less fertilizing. Sandy soils release nutrients faster, requiring more fertilizing. Container roses tend to require more frequent fertilizing.
Prior to planting your rose garden, it is a good idea to get the soil tested. This will give you an idea on how high or low the (N-P-K) levels in your soil are and guide you in choosing the proper fertilizer. A soil test will also tell you the pH level of the soil. Fertilizer applications can increase the acidity of the soil. Too much acidity in the soil may prevent the rose from absorbing the nutrients it needs, causing stunted growth. Roses are pretty good about telling you when they need help. Yellowing in the leaves can mean nitrogen is low. Greyish green leaves mean lack of phosphorus and if the margins of leaves turn brown, potassium is low.
Best Time To Fertilize Roses
You can begin fertilizing your rose shrub in the spring when you see the first 5-6 leaves emerge. Fertilize again after the first cycle of blooms is complete. Continue to fertilize after each bloom cycle. Stop fertilizing 6-8 weeks before the first anticipated frost as you do not want to encourage new growth that can be damaged by cold weather.
Newly planted roses should only be fertilized with phosphorus to help with the establishment of roots. Other fertilizers can be applied after the rose has bloomed. Container roses can follow the same guidelines but will require more frequent feedings.
Best Fertilizer For Roses
There are a lot of brands of rose food and fertilizers on the market, both organic and inorganic. No matter which brand or type you choose, make sure it has a well balanced N-P-K. Nitrogen helps the shoots. Phosphorus helps the roots. Potassium is like a vitamin for the entire plant. Roses are heavy feeders, so a combination of organic and inorganic can be an option. Organic fertilizers will give the shrub a steady supply of nutrients throughout the growing season. During peak blooming times, inorganic fertilizers can provide immediate nutrients for repeated blooming.
Organic fertilizers such as manure, compost, bone meal, fish emulsion, kelp, or alfalfa are better for the environment. Cost is usually higher for these types of plant food. You can make your own compost by using aged manure, yard debris, lawn clippings, or food scraps.
Inorganic fertilizers are ready-made and can be purchased at the store. They come in slow release, granular, or in liquid form. They are less expensive than organic fertilizers and are more convenient to use. It is best to remember that commercial fertilizers help the rose shrub but do not enrich and build up the quality of the soil.
Oftentimes, gardeners rotate their plant food between organic and inorganic options. It is best to follow the recommended feeding on the label of the fertilizer. Keeping your roses well fed will ensure beautiful blooms throughout the season.
Rose Fertilizing Tips
- Liquid fertilizers are best for young tender roses to prevent burning of the roots.
- A combination of organic and inorganic fertilizers is beneficial.
- Begin fertilizing in the spring
- End fertilizing 6-8 weeks before the first frost.
- Choose a fertilizer with a well-balanced N-P-K
- A soil test prior to planting will tell you what nutrients your rose needs.
- Water well before and after fertilizing.
- Container grown roses will require more frequent feedings.
-Always wear protective gloves and a face mask when handling chemical fertilizers.
-Closely follow all directions and storage guidelines that are on the fertilizer label.