Fertilize Spring Bulbs Now to Recharge Them For a Glorious Display Next Year – You'll Get Bigger, Brighter Blooms
Plus, experts reveal a big mistake to avoid making
Many of your spring bulbs will have finished flowering by mid-May. If you want to boost your daffodils, hyacinths, and tulips and give them the strength to flower again next year, it is a good time to fertilize spring bulbs.
Once the flowers go over, but the foliage is still going, it is a prime window to fertilize spring bulbs. A dose of nutrients, courtesy of a high phosphorus or potassium feed, at this pivotal time of the year, replenishes energy in the bulb. It ensures the bulb has all it needs to flower again next spring.
Here, we explain why you should fertilize spring bulbs after flowering and look at some of the best products to use. Plus, experts reveal the type of feeds you need to definitely avoid using, as it can ruin next year’s display of flowers.
The Ideal Times to Fertilize Spring Bulbs
The typical windows to fertilize spring bulbs are at planting time, in early spring when the shoots are emerging, and right after flowering. It does depend on your soil type, with more regular feeding required for those on poorer soils.
When you plant spring bulbs, add some balanced or high-phosphorus fertilizer and a layer of compost (like this organic compost at Amazon) to encourage the bulbs to develop strong roots.
Going forward, a balanced or specific bulb fertilizer (such as this Bulb-tone at Walmart) should be given once the first green shoots appear.
Gardeners can also fertilize spring bulbs after flowering to boost next year’s show, which is what we are focusing on here. So, let’s start with why you should fertilize spring bulbs this month.
Why Fertilize Spring Bulbs After Flowering?
If you want to guarantee a strong display from spring bulbs such as tulips, daffodils, hyacinths, crocuses, and more, feeding them after they finish blooming is a good step in the right direction. It may not be a common task among gardeners, but there are strong reasons to add this to your spring gardening checklist.
Lucie Bradley, a gardening expert from Easy Garden Irrigation with almost 30 years of industry experience, says feeding after they finish blooming helps bulbs to ‘replenish their energy’ so they can put on a repeat performance next spring.
‘This is the ideal time to boost the nutrients in the soil surrounding your bulbs using a liquid fertilizer high in potash (potassium), as this provides essential nutrients, strengthening the bulbs so they can store as much energy as possible,’ says Lucie.
‘You must get the timing exactly right, as feeding too early whilst your spring bulbs are still in full bloom, then they won’t absorb the nutrients as efficiently, so you will be wasting fertilizer. You need to wait until the blooms have faded, but the foliage is still green.’
A key part of bulb maintenance is to allow the bulbs to photosynthesize for as long as possible and store energy. That includes leaving the foliage in place and deadheading spent flowers so they don’t expend energy on making seeds.
Wait until the foliage has completely died back before removing it, which should be around 4-6 weeks after it stops flowering. At this time, it is also time to lift and divide bulbs to rejuvenate older clumps and boost your spring displays.
Encouraged to garden since she was old enough to walk, Lucie has been working in the gardening industry for over 28 years. This has meant she has been lucky enough to talk to both amateur and professional gardeners every day of the week and is always learning. She believes you can never know everything about gardening as it constantly evolves.
The Best Products to Fertilize Spring Bulbs After Blooming
A good feed to fertilize spring bulbs after they finish flowering is higher in phosphorus and potassium than in nitrogen. As there is a wide range of different feeds to choose from, what do some experts recommend?
David Trinklein, horticulture specialist for the University of Missouri Extension, says on the institute’s website that ‘organic fertilizers are good choices for bulbs’. He adds: ‘They break down slowly and release their nutrients over time, so there is a reduced risk of “burning” plant roots from excessive fertilizer.’
Jean Murray, Linn County Master Gardener, writes on the Iowa State University Extension website: ‘You can fertilize bulbs after they bloom. Use a 5-10-5 or 6-10-4 fertilizer.’ Plus, David Trinklein also highlighted 5-10-5 as a sensible NPK ratio for the job.
You can get Espoma garden food fertilizer at Amazon with an NPK of 5-10-5.
Lucie Bradley advocates for using liquid feeds, saying: ‘When fertilizing bulbs once they finish flowering, I would always recommend using a liquid feed high in potassium and low in nitrogen – such as a tomato feed – as I find that a liquid feed works faster and more efficiently than a granular feed when the bulbs still have green foliage.’
You can get an organic liquid tomato food at Walmart. Alternatively, this 5-10-5 liquid fertilizer is available on Amazon is an option if you want a liquid feed with NPK plant fertilizer numbers recommended by experts.
Liquid fertilizers are faster-acting than granular ones, so they make essential nutrients available more quickly. They also come with fewer issues of burning leaves, which can happen if granular fertilizer comes into contact with the bulb’s foliage.
One thing that all experts agree on is avoiding using high-nitrogen fertilizers. While David Trinklein highlights excess nitrogen promoting root rot, Lucie Bradley warns that this fertilizing mistake encourages more foliage rather than recharging the bulbs.
‘This means that the following year, even though you think you have fed your bulbs, they will make more foliage and fewer flowers,’ she says.
What to Shop
Bone meal with an NPK of 6-8-0 makes an excellent fertilizer when planting bulbs, as it encourages strong root development.
This fertilizer is designed for tomatoes and vegetables and has an NPK of 3-6-6. Apply around your plants, mix into the soil, and water in well.
An all-purpose fertilizer for bulbs with an NPK of 4-10-10. It can be used when planting bulbs or in spring to promote strong, healthy flowering.
If you are after more specific advice, we’ve got you covered. We have guides on when to fertilize daffodils and the best ways to fertilize tulips to help you get the best performances year after year.
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