Dahlias have fairly high nutrient requirements and, like other flowering plants, require plenty of potassium to bloom well.
David Hall, manager and director of Halls of Heddon, says that this flowering plant needs to be fed a potassium-rich feed in order to get the nutrients it needs:
“Dahlias respond well to regular feeding – but don’t overdo it. In the beginning, you can use a feed that is high in nitrogen. After a few weeks, a balanced feed works best.
“As soon as the buds appear, a tomato feed or a fertiliser high in potash should be used. This will help with stem strength and flower colour. ”.
Here are the three most important things you need to do to take care of your dahlias in an organic garden.
Dahlias are prized for their showy, colorful blooms that brighten up gardens from midsummer into fall To get the most prolific flowering from your dahlia plants, proper feeding is key One fertilizer that works exceptionally well on dahlias is tomato feed. The high potassium content helps produce stronger stems and more abundant blooms.
Why Tomato Fertilizer is Ideal for Dahlias
Tomato fertilizer is formulated to promote fruiting and flowering in tomato plants. The same properties that make it great for tomatoes also benefit dahlias. Here’s why tomato feed is an ideal choice:
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High potassium content – Potassium is the nutrient most vital for flowering. Tomato feed has extra potassium to fuel fruit and flower production
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Low nitrogen – Too much nitrogen leads to excessive foliage at the expense of blooms. Tomato fertilizer has reduced nitrogen.
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Added micronutrients – Micronutrients like magnesium and calcium contribute to plant processes needed for flowering. Many tomato feeds contain these.
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Acidity – Tomatoes and dahlias prefer slightly acidic soil. Tomato fertilizers help maintain ideal pH levels for these plants.
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Liquid application – Liquid tomato feeds allow for foliar absorption and quick nutrient delivery to aid flowering.
When to Start Using Tomato Fertilizer
When should you start feeding your dahlias with tomato plant food? Follow this guideline:
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Planting until sprouting – Use a balanced starter fertilizer to give developing tubers an early boost.
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Spring growth – Early rapid growth requires more nitrogen, so use a balanced all-purpose fertilizer.
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Flower bud formation – As soon as buds begin to form, switch to tomato feed to nourish the blooms.
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Peak flowering – Continue applying tomato fertilizer every 2-3 weeks through the main flowering period.
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Fall – Taper off fertilizer as plant energy goes back into the tubers in fall.
Adjust timing appropriately for your climate and the variety of dahlia you are growing.
Application Rate and Method
Always follow label instructions when applying any fertilizer. For tomato feeds, typical application rates are:
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Dry tomato fertilizer – Apply at 1-2 tablespoons per square foot. Scratch into soil around plants.
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Liquid tomato fertilizer – Mix according to label and apply 1 quart diluted solution per square foot.
Two key tips:
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Never apply dry fertilizer directly on plant leaves, as it can burn.
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For containers, use half the recommended rate to avoid buildup in the potting mix.
You can apply liquid tomato feed via soil drenching or foliar spraying. Foliar feeding is great for a quick boost when buds or flowers are developing. Homemade compost tea also makes an excellent foliar spray.
The Best Tomato Fertilizers for Dahlias
There are many quality tomato feeds on the market. When choosing one for your dahlias, look for:
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High potassium – Should be the first number on the NPK ratio.
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Added calcium and magnesium
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Options for liquid application
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Organic or synthetic formulas
Here are some top tomato fertilizer picks for dahlias:
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Espoma Tomato-Tone – Organic granular, also contains beneficial mycorrhizae
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FoxFarm Big Bloom Liquid – Concentrated organic formula for foliar or soil feeding
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Miracle-Gro Tomato Plant Food – Popular synthetic liquid fertilizer
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Neptune’s Harvest Tomato & Veg – Liquid formula with fish & seaweed oils
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Jobe’s Organics Tomato Granular Fertilizer – Time-released organic nutrient source
Tips for Using Tomato Fertilizer on Dahlias
Follow these tips to safely and effectively use tomato fertilizer on your dahlias:
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Test your soil pH and amend if needed – Tomatoes and dahlias prefer slightly acidic soil.
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Rotate fertilizers for balanced nutrition – Don’t rely solely on tomato feed; alternate with compost tea or all-purpose fertilizer.
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Watch for burn signs – Leaf burn can occur from excessive or direct application to foliage.
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Adjust rate for container plants – Use half strength tomato feed for potted dahlias.
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Complement with compost – Compost provides nutrients and improves moisture retention.
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Stop fertilizing in fall – Allow tubers to harden off naturally as foliage starts dying back.
The Results of Feeding Dahlias Tomatoe Fertilizer
When fed with a quality tomato fertilizer, here are some of the results you can expect:
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More blooms – The high potassium fuels increased flower production.
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Larger blooms – Key nutrients result in bigger individual blossoms.
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Bright colors – Pigments are enhanced, creating more vivid flowers.
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Stronger stems – Thicker, sturdier stems keep top-heavy plants upright.
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Extended flowering – Plants continue blooming prolifically into fall.
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Plant health – Nutrients strengthen the overall plant for better resistance to diseases.
Avoid Overuse of Tomato Fertilizer
While tomato feed is beneficial for dahlias, overfertilizing can be detrimental. Use the fertilizer as directed to avoid issues like:
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Excess foliage growth – Too much nitrogen leads to more leaves rather than flowers. Stick to the lower nitrogen tomato formulations.
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Root damage – Concentrated dry fertilizer on roots or tubers can burn and damage them.
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Flopped stems – Weak, floppy growth results from unbalanced nutrition.
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Fewer blooms – Excess nitrogen triggers more leaf growth instead of flowers.
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Smaller flowers – Some nutrients in excess can limit bloom size.
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Inhibited tuber growth – Too much fertilizer inhibits nutrient storage for next year.
Pay close attention to how your dahlias respond and adjust your feeding accordingly.
The Ideal Flower-Fueling Feed
Tomato fertilizer contains the ideal blend of nutrients, in the right ratios, to coax the most blooms from dahlias. Follow best practices for using tomato plant food, and your dahlia garden will put on a spectacular floral display!
Add Organic Matter During Flowering
As dahlias begin to flower, they will have the need for potassium to flower well.
To make sure there is enough potassium in the soil around your dahlias, you could add an extra layer of mulch made from leaves from plants that store potassium in a dynamic way.
Chenopodium album, Amaranthus, borage and comfrey are some plants that can be effective in gathering potassium.
The leaves of these plants can return nutrients to the soil when they are dropped on it around dahlias. This will help feed your plants.
Provide Healthy & Fertile Soil
Providing for any plant’s nutritional needs always comes back to the soil.
Dan Ori, a horticultural consultant, says, “I plant dahlias in compost or soil that I have mixed with granular controlled feed or continuous feed.”
“Use a 6 month controlled release product like Miracle-Gro all purpose continuous release plant food. That might be all that is needed for Dahlias that will be dug up in the fall that were planted outside.
“After 3 months, I would add a top dressing of granular feed mixed with fresh compost if you use an organic granular controlled release product like Miracle-Gro Performance Organics all-purpose.” ”.
Putting down mulch around your plants and replacing it every spring is a good way to keep the soil healthy, with all the nutrients and microorganisms and other soil life we need.
You should put down a layer of homemade compost, leaf mold, or well-rotted manure around your dahlia plants when you plant them.
This substance will help plants get nitrogen, phosphorus, and potassium, among other important nutrients. It will release these nutrients slowly over time.
The mulch will also help keep the soil moist and slow the growth of some weeds, which will make the dahlias grow better by giving them less competition.
How, What & When To Feed Dahlias For Stunning Blooms
FAQ
Do dahlias like tomato food?
What is the best fertilizer for dahlias?
Can you plant tomatoes and dahlias together?
Should I feed dahlias in pots?
Can you feed dahlia flowers?
A tomato food such as Lily Miller can be used to feed dahlia flowers as it has a low nitrogen content and will promote blooms. The potassium in the tomato fertilizer will stimulate blooms on both tomato plants and dahlias. Since they are low in nitrogen, coffee grounds can be an excellent fertilizer for dahlia plants.
Is tomato fertilizer good for dahlias?
Tomato fertilizers are typically high in potassium (or potash) and this is what stimulates bud and fruit production. Since tomatoes and dahlias have similar nutritional needs, tomato feed is often, surprisingly, a good fertilizer choice for dahlias during bloom. Product testing and review research take time, effort, and money.
Do dahlias need fertilizer?
This is because dahlia flowers do best with a fertilizer high in both potassium and phosphorous and low in nitrogen. This type of fertilizer is often referred to as bloom food, as it encourages the plant to produce more blooms. Giving your dahlias the right amount of fertilizer can make a big difference in the size and amount of blooms produced.
Can dachshund dahlias eat tomatoes?
To give your dahlias a speedy boost of potassium and other nutrients, you can also – during the flowering period – feed your plants with a potassium-rich organic, liquid plant feed. A feed suited to tomatoes will also suit dahlias well says Elaine Patullo from Dachshund Dahlia Plant Nursery: “A good quality feed is essential.
