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How to use fertiliser sticks

Updated: October 2026

Learning how to use fertiliser sticks is less about pushing a spike into a pot and more about controlling moisture, dose and timing. The nine products in our [fertiliser sticks comparison](/hub/fertiliser-soil-and-bark-mulch/fertiliser-sticks) claim release periods from 30 days to 12 weeks, yet most do not print a pot-size dose in the stored listing. That makes the physical pack your primary instruction source. Begin with moist compost, place the stick away from the stem, record the replacement date and avoid adding another feed on top. If the directions are missing or the root ball is too dense to insert a stick safely, stop rather than guessing.

Learning how to use fertiliser sticks is less about pushing a spike into a pot and more about controlling moisture, dose and timing.

Our top picks

Generic Devonia citrus and fruit fertiliser sticks

Best overall

Generic Devonia citrus and fruit fertiliser sticks
5.9/10about £7.99
View offer
Jobe's Organics Jobe's fertiliser spikes for fern and palm

Rank 2

Jobe's Organics Jobe's fertiliser spikes for fern and palm
8.1/10about £6.99
View offer
Substral Substral Naturen fertiliser sticks for herbs

Alternative

Substral Substral Naturen fertiliser sticks for herbs
6.0/10about £12.40
View offer
On this page
  1. 1.Water first, then insert the stick
  2. 2.Use the printed dose and set a diary date
  3. 3.Avoid stacking feeds and common insertion mistakes
  4. 4.If a child or pet swallows a stick

Water first, then insert the stick

Check the compost with a finger before you open the pack. RHS houseplant guidance says not to apply fertiliser to dry soil, and the same principle applies to a solid stick that releases with moisture. BBC gardening guidance describes poking sticks around the edge of a pot, and this keeps the feed away from the stem or crown. Insert the stated number of sticks and cover them with compost. Never force a rigid spike through obvious roots. One stored UK review for the Jobe's fern-and-palm spikes reports a pot-bound cycad dying after use. That single report cannot establish the cause.

Use the printed dose and set a diary date

Use the dose printed for the exact product, not a chart copied from another brand. Of the nine stored listings, only Substral Naturen gives a pot-size scale: one to five sticks according to pot size, with two per plant in a balcony box and replacement every two months. If your chosen pack simply says "insert into soil", check the delivered label or ask the seller rather than inventing a number. Set a phone or calendar reminder as soon as the stick goes in. Go Garden claims up to 30 days. Jobe's and Hiemible claim 60 days, while the generic 4-inch product and Substral Naturen say up to two months. Devonia all-purpose, tomato-and-vegetable and citrus-and-fruit sticks claim up to 12 weeks. These are seller-stated durations, not measured release trials, so the reminder is a review point rather than an automatic command to insert another stick. The houseplant fertiliser sticks guide explains that seasonal decision in more detail.
Generic Devonia citrus and fruit fertiliser sticks

Testsieger

Generic Devonia citrus and fruit fertiliser sticks
5.9/10about £7.99
View offer

Avoid stacking feeds and common insertion mistakes

Do not add routine liquid feed immediately after inserting a long-release stick. The product is already intended to supply nutrients over weeks, and a second feed makes the total dose difficult to judge. Claims such as "no overfeeding" or "controlled release" are seller wording, not proof that stacking products is harmless. Do not press a stick against the stem, crown or exposed roots, and do not gather several in one hole unless the pack specifically says so. In a balcony box, use the exact plant-based instruction on the Naturen pack rather than assuming every product follows its two-sticks-per-plant direction. The fertiliser sticks versus liquid feed guide sets out that trade-off, and the buying guide shows which listings provide enough information to dose confidently.

If a child or pet swallows a stick

Store unused sticks in their original closed package, out of sight and reach of children and away from pet food. Once inserted, cover them fully with compost and do not leave loose pieces on a pot saucer. None of the nine stored listings supplies a pet-safety test, so "organic", "natural" or plant-food wording must not be interpreted as safe to swallow. If a child may have swallowed fertiliser, do not wait for symptoms or try to make them sick. Use the product packet to identify the ingredients and contact NHS 111 for case-specific advice; call 999 for severe symptoms or an immediate emergency. For a pet, contact your veterinary practice or an emergency vet and keep the packaging available.

Common questions

Do I water before inserting fertiliser sticks?
Yes, if the compost is dry. Rehydrate it normally and allow moisture to spread through the root ball before inserting the stick. Fertiliser should not be applied to bone-dry compost. After placement, cover the stick and continue the plant's usual watering routine.
Where should a fertiliser stick go in the pot?
Follow the pack, but the usual position is in compost away from the stem and around the pot edge. Space multiple sticks rather than concentrating them in one hole. Never force one through a dense root ball or leave it exposed above the compost.
How many sticks should I use?
Use only the dose for that exact product and pot size. Substral Naturen is the only stored listing here that gives one to five by pot size. Other brands may use different stick dimensions and formulations, so borrowing its scale could underfeed or overfeed.
When should I replace a fertiliser stick?
Record the seller-stated interval when you insert it, then reassess at that date. Claims in this set range from 30 days to 12 weeks. Replace only if the product instructions, season and plant condition still support feeding; the claimed duration is not an automatic repeat order.
Can I use liquid feed at the same time?
Do not stack a new stick with routine liquid feed unless the exact product instructions tell you to. Combining feeds obscures the total nutrient dose and makes a reaction harder to correct. Choose one planned feeding system and keep an application record.
What should I do if the pot is root-bound?
Do not force the spike into the root mass. Address the root-bound condition, usually by appropriate repotting or plant-specific root care, before feeding. A liquid format may offer more control later, but it does not remove the underlying lack of root space.
What if someone swallows a fertiliser stick?
For a child, retain the packet and contact NHS 111; call 999 for severe or immediately life-threatening symptoms. For a pet, contact a vet or emergency veterinary service. Do not induce vomiting unless a qualified professional specifically instructs you to do so.

Related pages

Best fertiliser sticks

Fertiliser sticks

Fertiliser sticks buying guide: five checks to make

Fertiliser sticks for houseplants: season and light

Fertiliser sticks vs liquid feed: which format to pick

Sources

Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the nine amazon.co.uk listings captured on 19 October 2026. A mixing field is not a tested analysis. Organic wording has no certificate number in these files. The Substral 3,240 sample and the Go Garden 585 sample are not United Kingdom reviews.

  1. RHS, houseplants growing guide (retrieved 19 October 2026)
  2. RHS, nutrition and feeding plants (retrieved 19 October 2026)
  3. RHS, fertilisers (retrieved 19 October 2026)
  4. RHS, fertiliser labels explained (retrieved 19 October 2026)
  5. RHS, container gardening maintenance (retrieved 19 October 2026)
  6. RHS, citrus (retrieved 19 October 2026)
  7. GOV.UK, manufacturing and marketing fertilisers (retrieved 19 October 2026)
  8. Fertilisers Regulations 1991 (retrieved 19 October 2026)