Guide to planting hedges
Guide to Planting Hedges
Soil consideration for all hedging plants
Soil Improvement - Some advise that soil should be improved prior to planting and that backfilling should be done with materials other than the soil already in place, but the latest advice from the RHS is that there is little evidence that adding organic matter to the planting hole helps. However, many still feel it is good practice and particularly if your soil is on the poor side then you can improve it at a ratio of 2 parts soil to 1 part compost/organic matter/well-rotted manure.
Fertiliser - When hedge planting, particularly with bareroot plants, the use of bonemeal or RHS approved RootGrow is highly recommended as root growth is significantly improved and helps the plant to establish and grow much quicker. Bonemeal should not come into contact with the plant roots or stems, but should be mixed through the soil/compost and forked through at the bottom of the planting hole whereas RootGrow does need to be applied directly to the roots.
Hedge Plant Spacing
Beech, Privet, Holly, Hornbeam - Single Row 45 cm apart
Leylandii, Lawsons, Red Cedar - Single Row 60-90cm apart
Laurel, Yew - Single Row 45 - 60cm apart
Box (Suffruticosa/Dwarf) - Single Row 20cm apart
Box (Sempervirens) - Single Row 30cm apart
Quickthorn, blackthorn and mixed native hedges – Double row 6 per metre, 30cm between plants and rows, with staggering between rows.
Bareroot Hedging Plants
It is essential that the roots of bareroot plants do not dry out, so if it is not possible to plant bareroot upon delivery then extra care is needed.
If planting is delayed for less than a week, we advise that you keep the roots moist by soaking in water for an hour or two, draining, then rewrapping in their packaging and storing in a cool, dark, frost-free place. It is vital that the roots do not dry out, so check the roots every day or so to check that they are not getting dry.
If the delay in planting is longer due to waterlogged or frozen condition, the plants will need to be ‘heeled in’, do this by planting in a bundle in a shallow trench of moist soil, where they can stay for weeks until planting conditions improve.
- Bareroot plants should be planted as soon as possible once delivered, but avoid planting in very wet, windy, or frosty conditions. On a windy day, bare root plants can dry out very quickly if laid out on the ground, so ensure bareroot roots are kept moist right up until the point of planting and immediately prior to planting dip roots in a bucket of water so that the roots are wet prior to inserting in the soil.
- There are two types of planting methods for creating a hedge. The first is to create a trench, which will give better results in the long term but can be labour intensive in the short term. The trench needs to be twice as wide as the roots. Use a garden fork on the base and sides to loosen surrounding soil and create drainage holes and ensure it is completely cleared of all perennial weeds.
- The second method, which is less time consuming but may result in higher rates of plant failure, is to plant as you go by inserting a spade up to its depth, pushing the spade away from you to create a gap and then putting the bareroot in the gap then firming the soil back round.
- In both situations the roots should not be planted too deeply but at the same level as the ‘root collar’, this is identified by a bulge in the trunk just above the roots, or look for the high water mark left by the ground where the plant was growing before it was lifted.
- If using rabbit guards, coil the spiral around the plant, place the cane inside the guard and push it firmly into the soil.
- Firm the soil to eliminate air pockets, so as to prevent frost pockets forming which can damage the roots of the plant, but do not compact the soil down.
- Water each plant with approximately one full watering can per plant or more for plants over 1m tall.
Rootballed Hedging Plants
Rootballed plants can be stored for a few days, but ideally we advise planting them as soon as possible (particularly evergreens as they are less adaptable to being moved than deciduous plants). If planting is delayed then keep the rootball moist by soaking in a bucket of water for a couple of hours, draining then store in a sheltered spot, away from wind and frost.
- Soak the rootball in water for at least an hour prior to planting and make sure the planting hole is moist (not waterlogged).
- Rootballed plants can be planted in a trench or individually planted, in both scenarios the trench or planting hole need to be twice as wide as the rootball and it is vital not to plant too deeply and to plant at the same level as the ‘root collar’, this is identified by a bulge in the trunk just above the roots, or look for the high water mark left by the ground where the plant was growing before it was lifted.
- It is vital that the hessian or wire wraps around the base of the rootball are NOT removed, if removed the rootball can be significantly damaged and result in plant death. However, do loosen the wraps around the top of the rootball after it has been placed in the hole and firm the soil back around it.
- It is especially important with root ball plants that they are completely soaked after planting, this ensures that the soil will settle over the roots and fill up any tiny air pockets that could lead to frost damage.
Pot grown Hedging Plants
Pot grown plants can be left in their pots for a few weeks - just keep them well watered but not waterlogged.
- Soak the pot in water for at least an hour prior to planting and make sure the planting hole is moist (not waterlogged). Pot grown plants can be planted in a trench or individually planted, in both scenarios the trench or planting hole need to be twice as wide as the rootball and it is vital not to plant too deeply and to plant at the same level as the soil that surrounds it.
- If the roots from a containerised plant are tightly compressed then tease the roots out so that they are dangling rather than wound around the base of the plant.
- After it has been placed in the hole, firm the soil back around it to ensure there are no air pockets that could lead to frost damage. Water each plant thoroughly once planted.
Aftercare for all hedging plants
Mulch and keep weed free – Apply a bark mulch around the base of each plant (ensure mulch does not touch stem of plant as this can lead to rotting of the stem) to protect from frost, suppress weeds and help moisture retention. An annual mulch of well-rotted manure or garden compost to provide on-going nutrients will also help to establish the plant. Also, ensure weeds and grasses are kept away from the hedge base for the first few years, as they compete with the plants and can prevent them from establishing.
Watering – It is difficult to advise on the right amount of water, as soil and weather conditions are so variable, but too much or too little water can kill a plant. So use common sense, in particularly dry spells in early spring when the plants break dormancy they will benefit from regular soaking and on a regular basis until the plant is mature and established. Ensure that each plant is thoroughly drenched so that the water penetrates the root ball.
Firming In – As most hedging is planted in winter, when heavy frosts can break up soil and heavy winds can sway plants whose roots only have a tentative hold, keep checking the soil around the plants and refirm if required.
Pruning – Timing and amount to prune does vary widely between species, so it is best to check for the species you have, however for common hedging varieties the advice is as follows:
- Hawthorn, blackthorn and privet should be pruned straight after planting and the following season’s new growth to be reduced by about half.
- Other deciduous species should be only lightly pruned straight after planting and then in the first autumn after planting the annual growth should be reduced by a third.
- Evergreens should be left for at least a year, after which side shoots can be trimmed, while the leading shoot should only be trimmed once the hedge has reached the required height. Also, don’t be alarmed if evergreens and semi evergreens lose their leaves, or their leaves turn yellow – this is due to the stress of transplantation and can be remedied by making sure plant is adequately watered and new leaves will develop.