Clematis are popular climbing vines that produce gorgeous flowers in a variety of colors. With proper care, these plants can grow vigorously and bloom prolifically. One of the keys to success with clematis is feeding them the right fertilizer. Here is a complete guide to choosing and using the best fertilizer for your clematis.
Clematis Have Hungry Roots
Clematis are heavy feeders and need regular doses of nutrients to support lush growth and maximize flowering. Their roots aggressively take up nutrients from the soil. It’s easy for them to deplete soils of fertility. Providing supplemental fertilizer is important.
The Ideal NPK Ratios
The numbers on a fertilizer refer to the percentages of nitrogen (N), phosphorus (P), and potassium (K) it contains. This is known as the NPK ratio. Different plants need different proportions of these key nutrients
For clematis, look for fertilizers with an NPK ratio that has a higher percentage of phosphorus than nitrogen and potassium. Phosphorus encourages bud formation and blooming. A ratio like 5-10-5 or 10-15-10 is ideal. Avoid high nitrogen fertilizers which promote excessive foliage growth over flowers.
Organic or Synthetic Fertilizer?
You can choose organic or synthetic fertilizer for clematis. Organic options like bone meal, blood meal, chicken manure, and compost provide mild levels of nutrition. Synthetic fertilizers often result in bigger plants and more prolific blooms. But they have a higher potential to contaminate soil and water.
Granular vs. Liquid Fertilizer
Granular fertilizers provide slow, steady release of nutrients lasting 3-6 months Liquid fertilizers offer rapid uptake but must be applied more frequently Granular is generally easier to use while liquid gives more control over feeding.
How to Properly Feed Clematis
Follow label directions carefully to avoid fertilizer burn. Feed clematis when growth begins in early spring. Fertilize lightly at first, then increase dosage after several weeks. Stop feeding when buds form to encourage maximum blooming.
Granular fertilizer can be worked into the soil around plants. Liquid is either poured directly on the soil or diluted with water for a foliar spray. Stop feeding clematis altogether once they go dormant after the first hard frost.
The 6 Best Fertilizers for Clematis
1. Espoma Organic Bone Meal
This 4-12-0 organic formulation made from bones and phosphoric acid provides a natural phosphorus boost. It slowly releases nutrition over 2-4 months. The low nitrogen encourages abundant blooms. Can be mixed into soil or used to side dress.
2. Jobe’s Organics Flower Fertilizer Spikes
These pre-measured spikes offer organic nutrition in convenient application. Just insert into soil around plants. Their 3-5-3 ratio supplies steady feeding for 2-3 months with minimal risk of burn. Great for potted plants.
3. Jack’s Classic Blossom Booster
A versatile 10-30-20 water-soluble fertilizer that can be adjusted based on your soil’s needs. Use weekly at full strength in poor soils or dilute for richer soils. Promotes vigorous growth and prolonged bloom time.
4. Dr. Earth Flower Fertilizer
An organic 4-8-4 mix that includes probiotics and mycorrhizae fungi to stimulate soil biology and root growth. Provides slow release feeding for 2-3 months. Made from bone meal, chicken manure, sulfate of potash and more.
5. Miracle-Gro Shake ‘n Feed
These easy to apply 10-15-10 granules provide consistent feeding for 3 months. Just shake over the soil around plants. Contains nitrogen, phosphorus, potassium plus micronutrients. Feeds through the roots so safe for all plants.
6. Neptune’s Harvest Fish & Seaweed
A liquid 2-3-1 fertilizer made from fish emulsion and seaweed. It provides a quick nutrient boost with each application. Can be sprayed directly on leaves and soil. Builds helpful biology. Has a strong fishy smell.
Fertilizing Tips for Optimal Clematis Blooms
- Test soil pH and amend to 6.5-7.0 range if needed
- Mix compost into planting holes and topdress annually
- Apply low nitrogen fertilizer in early spring when growth starts
- Increase dosage gradually to avoid burn
- Use both foliar and soil feeding for maximum benefit
- Stop fertilizing when buds form to encourage abundant blooms
- Water thoroughly after fertilizing to avoid root damage
- Mulch around plants to conserve moisture and reduce weeds
With the right fertilizer and proper feeding techniques, your clematis will reward you with vigorous growth and masses of colorful flowers. Pay close attention to their needs, choose an appropriate fertilizer, and feed them regularly through the growing season. But avoid overdoing it, especially when buds start forming. A little timed fertilizer goes a long way towards growing clematis successfully.
Best Time to Fertilize Clematis
The best time to feed and fertilize your clematis is in the spring and in small amounts all through the growing season. You have two options: the simplest would be a slow-release fertilizer in spring. The ideal choice would be a balanced fertilizer such as 10-10-10 or a lower nitrogen type like 5-10-5. This will provide low-key, steady feeding.
More can be done to improve blooms. Every 4 to 6 weeks during the growing season, switch from a lower-nitrogen fertilizer to a balanced liquid fertilizer.
How to Fertilize Clematis
One of the first considerations is that Clematis prefer a neutral soil in the pH range of 5. 5-7. 0, so make sure your soil is in that range before you plant, whether it’s in a pot or a garden bed. Getting a test from the agricultural extension office in your county is the best and most accurate way to do this, but you can also use simple kits at home.
Agricultural lime can be used to make soil less acidic if it is too acidic otherwise. When you plant and mulch the roots to keep them cool and control how much nutrients the plant takes in, compost is a great addition.
Once your plant starts to make buds, switch to a fertilizer that is lower in nitrogen and higher in potassium and phosphorus. Too much nitrogen will encourage leaves to grow instead of flowers. This is especially important in spring when buds are about 2” long. After that, some experts say to switch between the lower-nitrogen fertilizer and a balanced liquid fertilizer like 10-10-10 every four to six weeks until August.
Keep the vines consistently well-watered, but not soggy, throughout the growing season for the best results.
Caring for clematis – Golden Rules
FAQ
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