Planting in Wet or Frozen Conditions

In an ideal world, when it comes to planting bare root fruit trees and bushes, soil and weather conditions will be perfect, but, of course, in reality, this is rarely the case. We therefore have to manage as best we can as we need to ensure the planting of bare rooted stock is undertaken in what is often the worst period of the year for weather – December to March! So how can we obviate the problems caused by adverse weather conditions?

Bearing in mind that wet ground followed by frozen ground are the main problems that we face I always advocate planting bare root bushes and trees as early as possible. Ground in early December is generally going to be much drier and warmer than in January to March so it is clearly best to take advantage of this. Coupled with the fact that there is still a little warmth in the ground in early December than there is likely to be in January onwards, fruit trees and bushes will benefit considerably by early planting as roots will start growing and be able to benefit the bush or tree come the move out of dormancy.

However, life is rarely as simple as this because we often either forget to order until too late to secure an early delivery, we fail to get an early delivery because the season is late or quite simply we don’t even contemplate buying until early in the new year. All of these factors have affected me over the years but somehow I have had to work my way through the resulting issues. Not sure how at times and particularly one year when I still had 30 trees to plant come the beginning of April – but that’s another story!

So before I look at adverse conditions – what can we consider as favourable planting conditions in winter? Most importantly the soil has to be workable, not only to be able to dig a planting hole but the hole needs to remain dry at the bottom and the soil friable enough to be able to shake it around the roots when backfilling. If a hole is dug in wet clay soil, the soil is “sloppy” or the hole fills up with water, you have entered the realm of unfavourable conditions and need to take steps to aid planting.

Assuming that you haven’t been able to plant early in good conditions you need to consider each factor as it is presented to you. Let’s start with wet conditions. Not all winter rain is horribly heavy and in some years – albeit far and few between – ground conditions have remained good throughout the winter. If you are worried about a period of heavy rain and flooding the first thing you could do is to make contact with your supplier and ask them to hold back on delivery for a short time. Alternatively and if you want to take delivery anyway you can keep dormant bushes and trees in a cool place such as a garage or shed for quite a few days without damage. Put the bushes and/or trees in plastic bags with the roots well insulated and keep the roots slightly moist through this storage. If there is a chance of frost during this period wrap the roots up well. Alternatively if you can find a piece of reasonable dry unused ground you can heel the bushes and trees in for a period. By heeling in I mean digging a small trench and laying your plants down with the roots in the trench and then covering up the roots. Make sure the covering soil is well firmed down. Trees can be stored this way for a considerable time and anyway this is a valuable method to use if you receive a large consignment which you simply can’t handle quickly.

You will need to keep an eye on ground conditions so that you can assess when planting conditions have improved. The test I discussed earlier is very effective – you simply cannot plant in a hole that quickly fills up with water and where the soil is only slimy handfuls. Planting bushes and trees in these conditions will lead to the roots either succumbing to rot during their first few months or simply becoming weak specimens. Now obviously you are not going to get perfect conditions as it is winter we are talking about but it is possible to improve planting conditions a little if ground conditions are not excessively wet. Providing you can dig a hole that doesn’t collapse and only fills up with a little bit of water it is possible to plant. The aim here is to use externally introduced soil such as imported topsoil or John Innes 3. When you have dug the hole, fork in a little organic matter and then a good few inches of imported soil. You can then go ahead with planting again using imported soil to bed in the roots and then only at the very end of planting draw back some of the previously dug soil over the top of the hole. Of course, you may be lucky to have enough friable soil to use that for planting but you will have to make that judgement. I used this method to plant a 20 tree orchard in March last year in foul ground conditions, used 20 bags of imported soil and all trees survived which pleased my client enormously as you can imagine!

Just a note on planting holes. You may be unlucky enough to live in an area where the soil water table is always quite high and where water will seep into a planting hole even in dry conditions. Again you will need to take precautions and the usual and by far best method to use is to raise up the planting level. As you simply cannot have roots sitting in a wet sump all year round you will need to create planting “mounds” whereby they may be up to 30cm (2ft) higher than the surrounding ground level. You can be fairly sure that this will obviate roots sitting in water and this method is used a lot in low lying parts of this country and other parts of the world of which Belgium and the Netherlands are good examples.

Unfortunately you may be in an area where you suffer with a permanent high water table and where the ground may be quite spongy during the whole year (particularly found in the redevelopment of old marsh or heath land) or a one off flooding situation when you are planting and where water levels are going to stay high for a fair length of time. In these conditions you are simply not going to be able to get bushes and trees in the ground either for a long time or indeed ever. In these conditions you are going to have to utilise raised beds (as a friend of mine in north Hampshire does) or growing them in pots or containers. Not the same but this is a need driven by necessity I’m afraid.

Having considered water and its effects on ground conditions we also need to consider frosty or freezing conditions. Ironically, unless weather conditions are very cold indeed – perhaps -5℃ and colder – ground covered by snow (once cleared away from the planting position), will be perfectly usable unless the ground is waterlogged.

In the same way that roots will simply rot off if they are sitting in water, they can equally be killed if they are frozen. This is why we always protect bare roots if stored in a shed or garage during very cold weather. Many gardeners are fooled into thinking that a frosted ground surface is not an issue and plant anyway. But this practice should not be followed as it is all too easy for a piece of frosted soil to end up in a planting hole where it can survive in that condition for sometime and very likely damage roots. What is the answer then?

If there is a very light frost on the ground you can water a large area with warm water to disperse the frost but this method should not be adopted until temperatures are 3℃ and rising. In any case this method is only practicable if you have one or two bushes or trees to plant. If you have heeled your plants in they can stay there until temperatures rise. If they have recently arrived and not yet heeled in, you can keep them in a shed or garage providing that the roots are well wrapped to prevent frost getting at them. I recommend that you also use some bubble wrap or similar to provide extra protection in really cold conditions. If freezing ground conditions continue for some time as they did in 2012 and 2013, you may need to consider planting in pots or containers for a few months to allow the roots to establish, planting them out later in the year as if they are pot grown plants.

For all of the reasons above once again I would emphasise the desirability of planting out early in the season, as invariably we do not tend to get freezing conditions in the UK until January/February.

Gerry Edwards
10th January 2015

Gerry is an experienced amateur fruit grower who is Chairman of the RHS Fruit Group, a member of the Royal Horticultural Society’s Fruit, Vegetable and Herb Committee and also their Fruit Trials Panel. Gerry judges fruit nationally for the Royal Horticultural Society and is also a qualified National Vegetable Society judge.