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Our last day for online orders is Thursday 19th December, all other orders will be processed on Monday 6th January.
We wish you a Merry Christmas and a Happy New Year!
Use code ’10OFF’ for 10% off
Our last day for online orders is Thursday 19th December, all other orders will be processed on Monday 6th January.
We wish you a Merry Christmas and a Happy New Year!
The term hardiness is used to indicate that a plant is able to withstand an average winter with very little or no damage to the plant. Some plants, especially those from northern latitudes, should be perfectly hardy, but if induced into growth during mild spring periods, then they may possibly be damaged by late frosts. Other plants may only be hardy if they have had sufficient sun during the summer to ripen their growth. The former plants should not be planted in frost pockets or sheltered positions, and the latter should receive as much sun as possible during the year. Plants not fully hardy may often be accommodated if planted in positions such as against a wall, or amongst, or under other trees and shrubs. Small gardens, particularly in built-up areas may often provide much more warmth and shelter than a larger, or more exposed garden.
| Rating | Temperature Range (C) | Category | Definition |
| H1a | More than 15 | Tropical – heated glass | Under glass all year |
| H1b | 10 to15 | Subtropical – heated glass | Can be grown outside in summer but performs better under glass |
| H1c | 5 to10 | Warm temperate – heated glass | Can be grown outside in summer |
| H2 | 1 to 5 | Cool or frost free | Will tolerate low temperatures, but does not survive if frozen. Requires glasshouse conditions. |
| H3 | -5 to 1 | Unheated glasshouse/mild | Hardy in coastal or mild areas except in hard winters or when at risk from sudden early frosts. Possibly hardy elsewhere with a sheltered wall or good microclimate. Will often survive with some artificial protection in winter. |
| H4 | -10 to -5 | Hardy – average winter | Hardy throughout most of UK except from inland valleys, at altitude and northerly locations. May suffer damage to foliage and stem dieback in harsh winters in cold gardens. Some normally hardy plants may not survive during long wet winters in poorly drained or heavy soil. |
| H5 | -15 to -10 | Hardy – cold winter | Hardy in most places throughout UK, even in severe winters, but may not withstand open or exposed sites in northerly locations. Many evergreens will suffer foliage damage. |
| H6 | -20 to -15 | Hardy – very cold winter | Hardy in all of UK and northern Europe. |
| H7 | Less than -20 | Very hardy | Hardy in severest European
Climates including exposed upland locations in UK. |
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