GARDEN BRIEFING · 23 SEPTEMBER 2026
Three September
garden notes.
A timely flower job, a useful pest-control window and a pesticide headline that needs a little context. Here is the practical version, with the sources attached.
1. Prepared hyacinths: a date worth noticing
The RHS September greenhouse advice recommends planting prepared hyacinths by 24 September if you want flowers for Christmas. That date is tomorrow, so this is a genuinely time-sensitive nudge—not a promise that every bulb will flower on a particular day. Follow the supplier’s instructions and keep the potting conditions appropriate for the bulbs.
The same RHS page recommends planting up Hippeastrum (amaryllis) bulbs in containers in September. That is a broader seasonal job if Christmas hyacinths are not on your list.
2. Vine weevil: biological control depends on conditions
RHS notes September as a suitable time to consider biological controls such as nematodes for vine weevil, because grubs begin hatching and soil or compost temperatures may suit them. Its advice is aimed at vulnerable plants, including fuchsias, succulents and container-grown plants.
That is not a blanket instruction to treat every pot. Check the product’s own instructions, target the plants that actually need attention, and make sure temperatures and application conditions are suitable.
3. Glyphosate in Great Britain: the review is still the story
The Health and Safety Executive says the Great Britain approval of glyphosate as an active substance has been extended to 15 December 2026 so its renewal assessment can be completed. The HSE says it is assessing whether the substance continues to meet the approval criteria; the page describes a future public consultation on its draft conclusion.
What that does not mean: it is not a new approval for every product or every use. HSE explains that active-substance renewals affect individual product authorisations through a separate process. Anyone considering a pesticide must check the current authorisation and follow that product’s label and legal conditions.
There is also a jurisdiction distinction: HSE says EU plant-protection rules continue to apply directly in Northern Ireland under the Windsor Framework. This briefing describes the Great Britain review, not one uniform rule for every part of the UK.
Why we keep the source links
Gardening advice can change with the season, product labels and local conditions. This is a dated summary of public guidance, not pesticide-use advice and not a report of work carried out in James’s greenhouse. We’ll check the source pages again before reusing the update after its date.
Sources checked 23 September 2026: RHS September greenhouse and houseplant advice, HSE: active substance renewal for glyphosate and HSE: effect on product authorisations. Verify current guidance and product labels at the point of use.