Independent comparisons. We may earn from shop links. More info

Systemic vs contact aphid spray

Updated: 22 October 2026

Two Provanto bottles sit in the basket and both say bug killer, yet one listing names flupyradifurone with contact and systemic action and eight weeks against aphids while the other promises contact and two weeks without printing an active on the twin-pack listing. Systemic vs contact aphid spray is the axis you need before harvest days or nozzle habit matter. The [Aphid killer comparison](/hub/pest-control/aphid-killer) lists all eight products. Peter F. checked these listings on 20 October 2026. This is not a lab test. A qualifying purchase can earn a commission at no extra cost to you.

Two Provanto bottles sit in the basket and both say bug killer, yet one listing names flupyradifurone with contact and systemic action and eight weeks against aphids while the other promises contact and two weeks

Our top picks

Provanto Provanto Smart Bug Killer, twin 1 L

Best overall

Provanto Provanto Smart Bug Killer, twin 1 L
9.4/10about £12.00
View offer
Provanto Provanto Ultimate Bug Killer, twin 1 L

Alternative

Provanto Provanto Ultimate Bug Killer, twin 1 L
9.4/10about £9.98
View offer
Growth Technology Ltd SB Plant Invigorator 500 ml

Best value

Growth Technology Ltd SB Plant Invigorator 500 ml
8.4/10about £8.53
View offer
On this page
  1. 1.Contact and systemic in one paragraph
  2. 2.Provanto Smart against Provanto Ultimate
  3. 3.What still needs a wet insect
  4. 4.The concentrate that says two things
  5. 5.Which to buy, with a condition

Contact and systemic in one paragraph

Contact insecticides kill aphids the spray touches and lose punch once the deposit dries or weathers. Systemic products move in plant tissue and affect pests that feed after treatment, within label rates and crops. Neither is a licence to spray open flowers on a bee-foraged courgette. Curled leaves still hide aphids from contact sprays; systemic action only helps if those aphids later feed on treated tissue and the label allows that plant. Physical contact sprays like SB Plant Invigorator rely on wetting without a named chemical on the amazon card.

Provanto Smart against Provanto Ultimate

Smart twin pack B0DDKV3GC3 costs £12.00 for two 1 litre ready-to-use bottles, lists flupyradifurone, contact and systemic action, aphids among targets, and up to 8 weeks against aphids, with 4.6 from 71 reviews and one comment that some aphids survived. Retailer label text for the ready-to-use Smart line mentions feeding stopping in about an hour; the twin-pack listing does not prove an eight-week garden trial. Ultimate twin pack B0DDKVTNY1 is £9.98 for two litres, contact, up to 2 weeks on the listing, 4.6 from 58 reviews, with thin review text. Ashwood and SDS sources for the Ultimate product family name deltamethrin at 0.0075 g/l contact spray; aquatic toxicity appears on professional sheets. The twin-pack listing does not print deltamethrin, so read the bottle. Eight weeks is not two weeks. Do not treat them as interchangeable on apples, brassicas, or greenhouse tomatoes; crop tables differ on retailer label copies. Flupyradifurone is a butenolide systemic active in label text; it is not the banned neonicotinoids clothianidin, imidacloprid, or thiamethoxam, and it is not bee-safe by default.
Provanto Provanto Smart Bug Killer, twin 1 L

Testsieger

Provanto Provanto Smart Bug Killer, twin 1 L
9.4/10about £12.00
View offer

What still needs a wet insect

Ready Steady Defend soap at £14.99 uses potassium salts and soya oils, contact only, 3.9 from 47 reviews with mite-heavy comments. SB at £8.53 is contact and physical with 2,429 reviews and no harvest interval stated on the listing. Both need coverage on visible aphids and repeats after drying. They suit you when you want a shorter residue story and you can soak leaves, compared with Smart when aphids hide and the label allows systemic use. Soap is poor value as the main aphid pick here; SB carries the review weight for physical contact. Neither replaces Ultimate’s two-week contact knockdown on large visible colonies when the label fits.

The concentrate that says two things

Provanto Smart Bug Killer concentrate B0C4BBNLF5 is 100 ml at £8.45, bullets claim up to 8 weeks and pesticide-free on the same amazon page, and do not name an active. A retailer description for the concentrate line mentions flupyradifurone and systemic action while repeating pesticide-free marketing. Do not assert one active or assume it matches the ready-to-use twin until you read the tub. A reviewer mentioned once-or-twice-a-year use limits at a low rate; that is a comment, not a bullet.

Which to buy, with a condition

Buy Smart twin when aphids on a label-approved crop need longer control and you will read harvest days on the bottle before eating. Buy Ultimate twin when you see aphids directly, want two litres under ten pounds, and accept two-week contact claims plus label tables. Buy SB when no harvest interval on the SB label matches your edible and you will respray both sides. Buy soap only for a named fatty-acid-style contact job you can reach often, not as default aphid cover. Skip treating systemic as a reason to spray flowering crops. Skip the concentrate until the tub resolves the pesticide-free conflict. Harvest waits sit on aphid killer for vegetables.

Common questions

What does systemic mean for aphids?
The plant takes up the active ingredient and affects aphids that feed on treated tissue afterward, within label crops and caps.
Why did the contact spray miss the ones in curled leaves?
The spray never touched them. Drying removed the residue before they moved.
Is Smart 8 weeks the same as Ultimate 2 weeks?
No. Different actives, modes, and label claims. Do not swap bottles without reading both labels.
Is flupyradifurone a neonicotinoid?
No. It is a different systemic class in label text. Still handle bees and flowers carefully.
Is the concentrate the same chemical as the ready-to-use Smart?
Unclear on amazon.co.uk. Retailer text conflicts with pesticide-free bullets. Read the tub.
When is a soap or SB the better contact choice?
When you can wet aphids directly, want a shorter systemic residue story, and accept repeats. SB carries the review depth and the no-interval line on the listing.
Does systemic mean I can spray open flowers?
No. The label and bee exposure rules still apply.

Related pages

Aphid killer buying guide

How to use aphid killer

Aphid killer

Best aphid spray UK: which listing fits your plants

Aphid killer for vegetables: harvest days on the label

Sources

Public UK sources used for this comparison. Shelf prices, stars and review counts are the amazon.co.uk figures captured for these eight listings on 20 October 2026. Last checked 22 October 2026.

  1. RHS, Aphids (retrieved 20 October 2026)
  2. HSE, garden and allotment pesticide use (retrieved 20 October 2026)
  3. HSE garden pesticide search (retrieved 20 October 2026)
  4. GOV.UK, action to protect bees from pesticides (retrieved 20 October 2026)
  5. RHS, grease bands and tree barrier glues (retrieved 20 October 2026)
  6. RHS, glasshouse whitefly (retrieved 20 October 2026)
  7. Tesco, Provanto Smart Bug Killer label text (retrieved 20 October 2026)
  8. Ashwood Nurseries, Provanto Ultimate Bug Killer (retrieved 20 October 2026)