Methods for Enhancing Peony Blossoms with Fertilizer
Peonies, beloved for their vibrant blooms, require careful attention when it comes to fertilization to ensure a bountiful display each season. With over two decades of horticulture study and gardening writing experience, Teo Spengler, a master gardener and docent at the San Francisco Botanical Garden, shares insights into the best practices for peony fertilization.
The type of fertilizer is crucial in promoting abundant flowering and strong roots. To achieve this, opt for fertilizers with low nitrogen content but higher phosphorus and potassium. Recommended fertilizer formulations include 5-10-10, 10-20-20, or 3-4-5 NPK ratios. These ratios ensure that the plant receives the necessary nutrients without promoting excessive foliage growth at the expense of blooms[1][3].
When it comes to frequency, peonies benefit from fertilization twice during the growing season. The first application should be made in early spring, when stems reach about 5-8 cm, and a second application mid-season. Over-fertilizing can lead to poor bloom production and overly lush foliage, which reduces flowers[3][5].
Slow-release or organic fertilizers are preferred as they provide steady nutrients without overwhelming the plant. Additionally, side-dressing with compost annually can be adequate if soil quality is good[5]. Apply half of the fertilizer in autumn, just after cutting back dormant plants, and the other half in spring when new growth appears. Fertilizer should be immediately watered after application to dissolve and blend it into the soil.
Established peonies do not require frequent fertilizer to produce flowers. After a few years, peonies usually only need fertilizer every three years or so, if at all. If soil is deficient in important nutrients, 3 or 4 ounces of a balanced (1-1-1 ratio) fertilizer per plant should suffice. Any balanced (1-1-1 ratio) fertilizer is suitable for peonies.
Testing soil is recommended to determine its nutrient content before adding peony fertilizer. Soil testing can help identify issues with the soil that may be affecting peony growth and blooms. Local extension offices can test soil samples and offer recommendations for soil amendments.
It is essential to keep fertilizer a hand's length away from the peony crown to prevent fertilizer burn. If soil does not need nutrients, no fertilizer is necessary for peonies. Adding compost to the soil can help maintain peony growth.
Starting off new peonies with rich, composted soil and fertilizing in spring and fall for the first few years sets them up for success. With the right care and attention, peonies will reward gardeners with a stunning display of blooms year after year.
[1] Spengler, T. (2020). "Peony Fertilization: How, When, and Why." The Spruce. Retrieved from https://www.thespruce.com/how-to-fertilize-peonies-1418765
[3] The Old Farmer's Almanac. (n.d.). "Peony Care: Fertilizing Peonies." Retrieved from https://www.almanac.com/plant/peony/care/fertilizing
[5] Cornell University Extension. (n.d.). "Peony Care." Retrieved from https://extension.cornell.edu/homegarden/fact-sheets/peonies-2/
Incorporating the recommended nutrients into your home-and-garden, consider fertilizers with NPK ratios such as 5-10-10, 10-20-20, or 3-4-5 for your peony plants. When attending to your peony's lifestyle, always remember to fertilize them twice each growing season, ensuring the first application is made in early spring and the second mid-season.
