UK Frost, Hardiness Zones & Sowing Dates

unrecordings

Thought I'd start a new thread on these subjects rather than derail the other long running threads.

Links to calendars, monthly to do lists & zone maps are most welcome as is the discussion of how helpful the H zoning system actually is (and is there confusion between the USDA system as applied to the UK versus the RHS system

Hopefully this thread will also help with the 'argh it's August, what can I sow' dilemma, and maybe help focus overactive minds in March/April.

To stay useful it might help to be made a sticky (hint hint)

unrecordings

So I’ll start. Here’s something I found to help locate your hardiness zone:

http://www.farmersknowbest.com/2019/01/uk-usda-rhs.html

a fairly useful monthly sowing guide from Real Seeds:

http://www.realseeds.co.uk/Monthlysowing.html

and another one with adjustable dates

https://www.gardenfocused.co.uk/adjust-dates-uk.php

unrecordings

In other news, after using my RHS membership to ask a couple of fairly pedantic questions I found out the following:

a) RHS have moved away from Hardiness based on zones and apply it solely on plants (given that the zoning system is inherently flawed without making it fiendishly complicated I guess)

b) That anecdotal evidence has shown that Spring comes to the tip of Cornwall about four weeks earlier than to the tip of Scotland

Karmacat

Very interesting! We're such a small country, but there's a month of difference. I wonder if thats not only the geographical distance but the clash of weather systems from the Atlantic, the Arctic and Europe?

unrecordings

Well the gulf stream is going to play some role in it rather than the pure latitude difference of say two points on the east coast, but thinking on I'm not sure how much the gulf stream wraps round the UK (quite a lot if not completely at a guess)

silverwhistle

What about west to east?

unrecordings

Latitude has more of a general effect as you're moving to/from the equator, into/away from the temperate zones. Longitude (east/west) only moves you into/out of local geography or climate features. For instance if I head due west I'll pretty much find myself on the peak of Kinder Scout. If I lived in Nottingham, heading to the same longitude west, would find a place much more pleasant

(in theory without checking a map, but I might be forced to check now :-)

unrecordings

unrecordings wrote: »

If I lived in Nottingham, heading to the same longitude west, would find a place much more pleasant ***

(in theory without checking a map, but I might be forced to check now :-)

Pretty much Alton Towers by the looks of it - I think I'd prefer Kinder, even in my condition

Davesnave

unrecordings wrote: »

Thought I'd start a new thread on these subjects rather than derail the other long running threads.


To stay useful it might help to be made a sticky (hint hint)

I didn't realise the stickies were still being updated by someone , so thanks for that. :A

Hardiness zones are a complex issue. I probably have at least two of them in my one property and I'd guess that it's the same for many others. Plant something here in our frost pocket and that might be the last anyone sees of it! Up on the hill, in the shelter of a hedge or wall, might be fine.

Also, plants that are labelled as tenderish, say, H3, sometimes behave differently. The winter of 2009/10 here saw what looked like mass extinctions of some plants in that category, only for them to bounce back from the base and thrive ever since. This indicates one might often be better planting these 'sensitive' plants rather than keeping them potted and moving them indoors when the weather turns, especially if it's just to the minimal protection of a polytunnel. That again depends heavily on soil conditions. Where I am, good drainage might be the key to success as much as aspect and shelter.

Anyway, interesting reads. Thanks.

Davesnave

unrecordings wrote: »

anecdotal evidence has shown that Spring comes to the tip of Cornwall about four weeks earlier than to the tip of Scotland

Anecdotally, we find that our area in Mid Devon is about 2 weeks behind places on the coast, like Dawlish.

This is due to the lesser maritime influence and altitude. We're 500' above Dawlish.

We're also in a small rain shadow area, missing the deluges that affect higher land north and south of us and on the Atlantic coast, so it isn't all bad!

unrecordings

If you're so inclined (and have enough time on your hands to think) it's fascinating to consider all the little local conditions that make up your small holding/plot/garden. I'm just in the lee of the pennines so a lot of the nasty stuff from the west tends to pass right over us but at a more local scale, anything from the north tends to rake down the treeline of the woods at the bottom of the garden