How To, Jorge, Plants, Trees

Scrumptious on a MM106 (left) and M27 rootstock. Note the difference in foliage and stem thickness.

Nobody should purchase an apple tree without first considering its rootstock. Rootstocks determine a tree’s size, resistance to disease and time to fruit. Primrose recommends you buy a dwarfing rootstock if you are interested in maximising productivity. For most gardens in the UK, an apple tree grown on its own roots is simply too large!

What is a Rootstock?

A variety grafted onto a rootstock.

Rootstocks are plants, usually of the same species, selected for their interactions with the soil. It is these plants that your selected apple variety will be attached in a process known as grafting. Thus, the Cox apple tree that you buy isn’t entirely a Cox as its roots are a different variety.

Apple trees have to be produced this way as their seeds aren’t true to type. Apple trees need to exchange chromosomes to produce offspring just like humans. Thus, if you plant a Cox apple and it germinates your resultant tree won’t be a Cox, but a mix between a Cox and another apple variety.

Not only are rootstocks necessary for propagation, they affect the variety they are attached to. One of the most important effects, is how a rootstock affects a tree’s eventual size. Thus, rootstocks are categorised into dwarfing and vigorous rootstocks, with dwarfing producing smaller trees and vigorous larger.

fruit tree rootstocks
The commonest rootstocks of some popular fruit tree species.

Dwarfing rootstocks produce smaller trees as they are worse at gathering resources. This may sound like a bad thing, but it is actually a huge benefit. Trees will put more effort into fruiting at the expense of vegetative growth as they want to pass on their offspring. This makes your tree more efficient. A higher percentage of carbohydrates go into fruits than leaves and stems.

This leaves us with this simple rule of thumb. If you are interested in maximising space and maximising output, dwarfing rootstocks are a must. If you want to grow your tree for ornamental value, buy a vigorous rootstock.

Is there anything else I need to know about rootstocks?

As rootstocks affect other traits than a tree’s size, such as disease resistance, you should factor such traits into your calculations. Importantly, it is hard to determine how a rootstock, variety and local conditions interact before planting. Thus, if you wish to establish an orchard, buy multiple varieties on different rootstocks to test the waters before any big outlay.

With dwarfing rootstocks, it is important that they are supported with ties, stakes or poles. Such trees produce heavy crops relative to their size and will lean or fall over; their roots are shallow and brittle and liable to uprooting in severe weather.

History of Apple Rootstocks  

Use of rootstocks goes back thousands of years, but it wasn’t until the 1800s when they were referred to by name. It is this period that provides us with two examples – Paradise (French Paradise) and Doucin (English Paradise) – of which the latter was more vigorous than the former. Common as these rootstocks were their ubiquitousness may have been due mislabelling and mis selling, rather than widespread propagation. One author from the late-1800s sussed this out, describing 14 different kinds of Paradise rootstocks.

It wasn’t until the early 20th century when the East Malling Research Station set upon determining the trueness of the Paradise rootstocks. Unsurprisingly, the institute found numerous misnamed and mixed collections of plant materials and decided to abandoned their names entirely assigning a number to each, giving us the original M (Malling) series of 24 rootstocks. Unfortunately, they weren’t numbered according to tree size with M9 smaller than M2.

Controlled crosses produced the famous M26 and M27 rootstocks. The MM106 and MM111 were produced once the John Innes Institute of Merton joined with East Malling in developing rootstocks resistant to wooly aphids. Thus here, MM means Malling-Merton.

In the 1960s work began to remove viruses from the rootstocks as to reduce incompatibility. (Viruses can cause a graft not to take). The first rootstock cleaned was the M7 which became M7A. Unfortunately, removing viruses led to a loss of size control with the dirty M9 producing smaller trees than the cleaned M9 (known as M.9EMLA with EMLA standing for East Malling & Long Ashton research stations). Eventually, all M series rootstocks were cleaned.

Other countries around the world set on developing rootstocks suited to their climates with the Budagovsky series developed at Michurinsk College, Russia and the P series developed in Poland, both seeking cold hardiness. (As cold hardiness is unnecessary in the UK, these rootstocks are not widely used by nurseries).

A more research breeding program led by Cornell University has produced the Geneva series of rootstocks with a special emphasis on resistance to fire blight. This series you are more likely to see in the future, due to the emphasis on disease resistance.

List of Apple Rootstocks By Size (Smallest to Largest)

apple tree rootstock infographic
Approximate apple tree eventual heights by rootstock. We have taken growing conditions as optimal and presumed the tree is a Cox.

Note: standard refers to a tree grown on its own roots. Thus a rootstock that produces a tree 30% of standard will produce a tree 70% smaller than if it was grown on its own roots.


Perfect for small gardens, M27 will produce a tree 30-50% of standard and is very precocious (produces early in its life). With the Cox variety, you can expect a tree 1.5-2m high.

It is highly susceptible to fire blight but resistant to crown and root rot. It produces few burrknots and root suckers.

Permanent support is recommended. Leader support will produce larger trees.

The tree was produced in 1934 at East Malling and is a cross of M13 and M9.


M9 will produce a tree 45-50% of standard and is very precocious. With the Cox variety, you can expect a tree 1.8-2.5m high.

It is very susceptible to fire blight and woolly aphid, but fairly resistant to crown and root rots.  It produces a moderate amount of root suckers and many burrknots.

Permanent support is recommended. Leader support is necessary. Unsuitable to wet sites.

The tree was selected from a group of French genotypes “Juane de Metz” in the late-1800s. It is the most widely used rootstock in the world.


M26 will produce a tree 55-60% of standard and is precocious. With the Cox variety you can expect a tree 2.5-3m high.

It produces many burrknots and is susceptible to to crown rot and fire blight.

Usually requires support. (Possibly forgo in sheltered sites.) Unsuitable to wet sites.

The tree was produced in 1929 at East Malling and is a cross of M16 and M9.


MM106 will produce a tree 70-75% of standard and is somewhat precocious. With the Cox variety you can expect a tree 3.5-4m high.

It is resistant to woolly aphid, susceptible to crown and root rot and fire blight and hypersensitive to tomato ringspot virus. It produces few burrknots and root suckers.

Support is unnecessary. Unsuitable to wet sites.

The tree was produced in 1932 by John Innes and East Malling and is a cross of M2 and ‘Northern Spy’.

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

Composting, George, How To, Mice & Rats, Pest Advice, Pest Control

Composting is a great way to reduce the waste you send to landfill and produce organic fertiliser for your plants. One of the biggest concerns around having a compost bin in the garden is whether it might attract pests or vermin. The short answer is yes, it can. But that’s why we’ve gathered advice to ensure you can build a pest-proof compost bin and enjoy all its benefits without the pain.

pest proof compost

Why are pests attracted to compost bins?

The most likely pests to seek out you compost are rats and mice. They are a common part of a residential ecosystem and look for two things: food and shelter. This is why rodents are particularly attracted to compost heaps, especially in winter. It provides them with food and a warm, sheltered spot to sleep in.

Insects, however, are generally nothing to worry about in compost heaps. Worms, slugs, millipedes, spiders, beetles and more are regular guests. They are a crucial part of the decomposition process, so embrace the bugs!

slug compost

Tips for deterring pests

  1. Avoid putting any meat or dairy products in your compost, including fatty oils or bones. This would smell like a feast to rats.
  2. Over autumn and winter keep your compost bin damp – this will help with the decomposition process and make it less attractive to rodents.
  3. They also don’t like disturbance, so be sure to turn your compost regularly or give the bin a kick when you walk past!
  4. Cover food scraps with dry leaves or soil in the bin to conceal the smell of decaying food.
  5. Rodents are reportedly put off by the aroma of mint, so try sprinkling peppermint oil on your compost or planting mint nearby.

mouse in garden

How to protect your compost bin

It’s very hard to completely protect a compost bin against vermin as mice can squeeze through holes as small as a penny, and rats can chew through almost anything. Compost bins are much easier to seal against invading pests than open heaps, so if you’re worried about rodents then they’re the better choice. Surrounding your bin with rocks and bricks can make it a bit more fortified.

If you have a plastic bin, this is easiest to seal. The best time is before you start using it as you’ll need to line the bottom with wire mesh. Ensure the holes are only small enough for bugs to get through, not burrowing mice.

If you have a wooden bin, again you’ll need to line the bottom and sides with wire mesh. Make sure this is sealed firmly round all the edges with no gaps.


Last resorts

Hopefully these tips will make your compost bin as unattractive to pests as possible. While the best defense is prevention, if you’re still experiencing issues then it might be time to look into pest control, such as traps.

Happy composting!

George at PrimroseGeorge works in the Primrose marketing team. As a lover of all things filmic, he also gets involved with our TV ads and web videos.

George’s idea of the perfect time in the garden is a long afternoon sitting in the shade with a good book. A cool breeze, peace and quiet… But of course, he’s usually disturbed by his energetic wire fox terrier, Poppy!

He writes about his misadventures in repotting plants and new discoveries about cat repellers.

See all of George’s posts.

Gardening Year, Guest Posts, Plants, Trees

Japanese gardens are designed to reflect the distinct beauty and passing of the four seasons. Autumn brings a light relief from the heat where sunny and less humid days takeover, giving way to cooler nights. A magical time of change when stunning and vibrant Japanese Maples glow a fiery red amongst lush moss and ferns.

By contrast, the cold and snow of winter is a time for evergreens to take centre stage. A winter garden is known for its myriad of greens, and there is a sense of peace and tranquillity as plants rest and trees reveal their intricate forms – the perfect place to escape from the distractions of our busy lives.

So if you’re looking for a little autumnal inspiration for your Japanese garden, here are some of the best Japanese plants for the cooler months.


Sango Kaku – Japanese Maple

Breathtaking in the autumn, the Japanese Maple (also known as Acer Palmatum) is widely used in Japanese gardens, and is famous for its striking red leaves and beautiful foliage. Cultivated in Japan for over 300 years, this deciduous tree is a slow growing plant that typically lives for over 100 years.

The species thrives in acidic and loam-based compost that contains high levels of organic matter. The Japanese Maple however won’t tolerate wet, dry or alkaline conditions, and their lacy, finely cut leaves require partial shade in the summer to avoid any damage from the sun.

Kuromatsu – Japanese Black Pine

The Japanese Black Pine represents longevity, and is mostly found in the coastal areas of its native Japan. The tree can reach up to 30 feet in its natural surroundings, and can tolerate temperatures as low as minus 25 degrees.

One of the most classic bonsai trees, it is tough and hardy, typically growing in stony soil where it survives harsh coastal winds. The tree is irregularly shaped and dark grey-green in colour, its needles are in fascicles of two, with a white sheath at the base. Resistant to salt and pollution, it’s commonly used in a variety of Japanese gardens, but above all it is a beautiful ornamental tree.

Ume – Japanese Apricot

The Japanese Apricot is a deciduous tree that can be found in sparse forests, by streams and in the mountains. It is most commonly planted in the north east of Japanese as the fruit is thought to be a protective charm against evil, the direction from where evil is supposed to come. Flowering in late winter around January or February, its blooms are snow-white or blood red, representing the floral symbol of January.

How to Grow Moss in Your Garden


Lush, green, velvety moss has been a central element of Japanese gardens for centuries, and is stunning in the autumn when it contrasts with maple trees. It can cover large areas of the garden, growing on stone lanterns, trees and garden stones. Its overall aesthetic portrays an ancient ambience, providing an ethereal sense of rugged beauty.

Thriving in humid, wet environments, Japan has one of the richest environments for moss, and with the ability to hold up to 20-30 times of its own weight in water, it can thrive in nutrient-poor soil where flowering plants have a harder time to survive.



Bamboo is an evergreen that’s integral to almost every type of Japanese garden. It has a variety of uses, including the formation of hedges, fences and is frequently used to help create shade. Found near rivers and in the mountains, bamboo is also used in strolling and tea gardens, where the sound of the wind rustling through their leaves adds to the tranquillity of any Japanese garden.

While there exists a variety of different types of bamboo, these can are broadly categorised as either clumping or running bamboo. Typically clumping bamboo is found in either tropical or sub-tropical regions, and although there are a few varieties that can deal with colder temperatures, not all of them will be suited to the temperate climate of the UK.
By contrast, running bamboo usually originates in colder climates, with many varieties staying green and leafy down to about zero degrees, with a few coping well in conditions of up to minus 15 degrees.



What Japanese garden would be complete without a fern? They’re one of the most ancient plants, with their thick, green foliage offering an eye-catching accompaniment to a variety of trees and shrubs.

Throughout Japan there are hundreds of native species and many of those have been successfully cultivated in European and American gardens. They grow best in shady and moist environments, thriving out of the sun where their large luscious leaves have evolved to help them cope with life in the shade. Ferns also group well together, and beautifully complement plants like the stunning and vibrant Japanese Maple.

Enkianthus shrubs

Often found colonising mountain slopes in Japan, the E. Campanulatus is the hardiest of the Enkianthus species, boasting spectacularly bright green foliage that turns into vibrant colours of red, yellow and orange during the autumn.
This hardy, deciduous shrub can survive harsh winters, before producing clusters of pretty bell-shaped spring flowers that are cream in colour with striking pink veins. The plant thrives in acidic, well-drained soil and can survive temperatures as low as -20 degrees.

Autumn is one of the most beautiful times to visit a Japanese garden as the Japanese Maple shows off its red and golden hues in the autumnal sunshine, with the simplistic beauty of evergreens during the winter often providing a noticeable contrast against the falling snow. By emphasising and focussing on plants that thrive throughout the four seasons, you can ensure your Japanese garden remains a place of beauty, serenity and calm all year round.

This post was written by James Stedman of Japeto, a family owned business who offer an extensive selection of handpicked, high quality Japanese gardening tools, developed for professional and amateur gardeners.

Gardening, Grow Your Own, Megan

Garlic. It’s one of the most important ingredients in cooking. In the same family as onions and shallots, garlic is bursting with a bold savoury flavour, making it a staple in many of the world’s cuisines. It is one of those ingredients many people always have in their cupboards. But what about their gardens?

You can grow dozens of garlic bulbs from single cloves, giving a great return rate. Growing garlic is very simple, and autumn is the perfect time to start planting cloves. To find out more about growing garlic in your garden, so you never run low on this essential ingredient, read on!

Growing Garlic - Garlic Bulbs

Garlic Varieties

With an abundance of garlic varieties available, it can be hard to know which one to choose. Whilst softneck varieties are the most common type found in supermarkets, they are best suited to the milder climate of the south due to hardiness. Hardneck varieties are hardier, more suited to the climate and can be grown all over the UK.

  • Chesnok White – with purple striping bulbs, this hardneck variety has a strong flavour which makes it great for garlic bread
  • Bianco Veneto – a softneck variety that thrives in colder conditions and stores well
  • Early Purple Wight – bred on the Isle of Wight, the purple-tinged bulbs of this softneck variety are best used within three months
  • Iberian Wight – originating from Spain, Iberian Wight is a softneck variety which produces large cloves
  • Solent Wight – also bred on the Isle of Wight, this softneck variety is particularly suited to the UK climate and is an overall winner in terms of taste and lifespan. Its large bulbs are easily plaited.
Growing Garlic - Garlic Bread
Garlic Bread


As mentioned previously, garlic is best planted in autumn to late winter when the temperature is cooler. Planting depends widely on climate. In milder southern regions, cloves can be planted directly into the ground and protected with cloches. If you live a colder part of the country, plant cloves in seed trays ready to set out into the ground in early springtime.

Planting garlic is pretty simple. Each clove will produce a plant. Preferably, buy your chosen variety from a garden supplier rather than the supermarket, as these will be especially bred for the local climate. Break the garlic bulb up into cloves, being careful not to damage them.

If planting directly into the ground, after preparing your soil, simply push the cloves into the soil at 10cm intervals. Make sure the tip of each clove is left exposed.

In colder areas, fill a seed tray with multi-purpose compost and plant one clove in each space. Water and place in a cold frame; the garlic plants should be ready to be planted in the ground from march onward.

Growing Garlic - Garlic Cloves


Growing garlic is relatively low maintenance, so you will not have to be tending to you garlic for hours each day, you will be pleased to hear. Just ensure you weed between the plants so that the garlic plants have enough space and there is less competition for water. If your garlic plants begin to flower, remove them as soon as possible, but do not throw away! These flower stalks are great in salads and stir fries. If the flowers are left, the garlic will produce a smaller yield.

To ensure the juiciest bulbs, check to see if the soil is dry every couple of weeks, and water sparingly if there is a dryer period.

Growing Garlic - Garlic Flower
Garlic Flowers


Garlic is ready to be harvested in early summer. The telltale sign is when the leaves of the garlic plant turn yellow and begin to wither. To extract the bulbs from the ground, take a trowel and loosen them taking care not to cut them; this reduce the length of time they will store for. If the bulbs are left too long, they will re-sprout or start to rot in the ground so make sure to harvest them opportunely.

Growing Garlic - Trowel


Lay the garlic bulbs out in a warm place until they are dry. Garlic can be stored by plaiting the bulbs together and storing in the kitchen. Alternatively, keep garlic in a bowl containing holes to ensure the bulbs are able to ‘breath’. Do not make the mistake of storing garlic in the fridge – it causes bulbs to go off faster. Garlic stores best at room temperature.

Growing Garlic - Garlic Bulbs

Overall, growing garlic is easy, low maintenance and hassle free. Plus, you’ll never be low on garlic again!

Megan at PrimroseMegan works in the Primrose marketing team. When she is not at her desk you will find her half way up a hill in the Chilterns
or enjoying the latest thriller series on Netflix. Megan also enjoys cooking vegetarian feasts with veggies from her auntie’s vegetable garden.

See all of Megan’s posts.