When buying grafted apple seedlings, the variety is only half of the decision. The rootstock determines much of the tree’s eventual size, vigor, anchorage, precocity, planting density and management requirements.

Two of the most widely known apple rootstocks are M9 (Malling 9) and M26 (Malling 26). Both are dwarfing rootstocks, both encourage relatively early fruiting, and both can support intensive apple production. However, they are not interchangeable.

In simple terms, M9 is smaller and more dwarfing, while M26 is more vigorous and produces a larger, somewhat stronger tree. M9 is particularly suited to high-density orchards where irrigation, nutrition, pruning and permanent support are well managed. M26 provides a useful middle ground for farmers who want a relatively compact tree without going as strongly toward the intensive system associated with M9.

What Does an Apple Rootstock Do?

An apple tree consists of at least two genetically different parts: the scion, which determines the apple variety and much of the fruit characteristics, and the rootstock, which forms the root system and influences the growth of the tree.

For example, a farmer may plant a ‘Gala’ apple grafted onto M9 or the same ‘Gala’ grafted onto M26. The fruit variety remains Gala, but the resulting trees can differ considerably in size and management requirements.

Rootstock influences:

• Tree size and vigor
• Age at first significant cropping
• Yield efficiency
• Root anchorage
• Planting density
• Water and nutrient requirements
• Tolerance or susceptibility to some soil and disease problems
• Pruning and training requirements

This is why choosing between M9 and M26 is really a decision about the type of orchard you intend to operate.

M9 Apple Rootstock

M9 is one of the best-known dwarfing apple rootstocks in commercial apple production. Extension sources generally place M9 trees at roughly 40–50% of standard tree size, although the actual size varies with the M9 clone, scion variety, soil, climate and management system.

It is highly precocious, meaning trees begin producing fruit relatively early. It also has high yield efficiency: the tree can produce substantial crops relative to the amount of vegetative growth it makes.

This is one of the major reasons M9 is attractive for high-density orchards.

The major advantage of M9

The biggest advantage is size control.

A smaller tree allows more trees to be planted in a given area. It also makes pruning, spraying, thinning and harvesting easier because much of the canopy remains accessible.

However, this advantage comes with a management requirement that farmers must take seriously.

M9 requires permanent support

M9 has relatively weak natural anchorage. Its root system is not sufficient to reliably support a heavily fruiting tree, particularly under windy conditions or where the crop load is high.

Consequently, commercial M9 orchards generally require a permanent support system such as a trellis or strong individual support.

This is particularly important when calculating the establishment cost of an M9 orchard.

The cost of the seedling is not the total cost of establishing an M9 orchard. The farmer should also budget for posts, wires, ties, installation, irrigation where required and ongoing canopy management.

M26 Apple Rootstock

M26 is also a dwarfing rootstock, but it is more vigorous than M9.

Depending on the source and growing conditions, M26 commonly produces a tree around 50–60% of standard size. Some references give approximately 40–50%, illustrating why rootstock percentages should be treated as approximate rather than as an exact prediction of tree height.

M26 is also precocious and productive.

Because it has greater vigor than M9, the tree generally develops a larger canopy and has somewhat greater capacity to establish itself than a tree on M9.

M26 therefore occupies an intermediate position between strongly dwarfing rootstocks such as M9 and more vigorous rootstocks.

M9 vs M26 at a Glance

The figures are general rootstock characteristics; actual tree size and performance depend on cultivar, soil, water, climate and orchard system.

Which One Produces the Smaller Tree?

M9.

This is the clearest difference between the two.

M9 deliberately restricts vegetative growth. That allows farmers to establish relatively high-density orchards and keep trees manageable.

M26 permits more vegetative growth and consequently produces a larger tree.

This difference matters because tree size affects almost every other aspect of orchard management.

With M9, you can potentially put more trees into the same area, but you must manage those trees intensively.

With M26, you generally need more space per tree, but each tree has greater vegetative capacity.

Which Rootstock Fruits Earlier?

Both M9 and M26 are considered precocious, meaning they encourage relatively early production compared with more vigorous rootstocks.

However, M9 is particularly well known for very early bearing and high yield efficiency. USDA and extension rootstock tables describe M9 as very early bearing and very productive, while M26 is also described as very early and productive.

This makes both attractive to commercial farmers who do not want to wait many years for a large conventional apple tree to reach full production.

But there is an important principle here:

Early fruiting does not mean the farmer should allow a young tree to carry an excessive crop.

A heavily cropped young tree can struggle to establish sufficient canopy and root development.

The objective during the early years is to build the permanent structure of the tree while allowing controlled fruiting.

Which Has Better Yield?

This question needs to be handled carefully.

It is tempting to ask:

“Does M9 produce more apples than M26?”

The more useful question is:

“Which rootstock produces more apples relative to the space and vegetative growth it occupies?”

M9 has very high yield efficiency, making it particularly attractive for high-density systems. M26 is also productive but produces a larger tree.

Therefore, an M26 tree may produce a substantial crop per tree, but M9 can be highly efficient when yield is considered against tree size or orchard space.

Actual yield per acre or hectare depends heavily on planting density, cultivar, irrigation, nutrition, pollination, pruning and orchard management.

So it would be misleading to promise a specific yield simply because a tree is grafted on M9 or M26.

Which Rootstock Allows Higher-Density Planting?

M9.

Because the trees remain smaller, M9 is particularly suited to high-density systems.

This can be a major advantage where land is limited or where a farmer wants to maximize production from a relatively small orchard.

But high density is not simply a matter of putting seedlings close together.

A high-density M9 orchard needs:

• Reliable water supply
• Good soil fertility management
• Permanent support
• Regular pruning and training
• Good weed control
• Appropriate pollination
• Careful crop-load management

If these components are missing, high-density planting can create a crowded orchard with weak trees and poor light penetration.

What About M26?

M26 allows a farmer to establish a less intensely packed orchard than M9 while still maintaining relatively compact trees.

This can be attractive where the farmer wants a manageable orchard but does not want to invest as heavily in the infrastructure and intensive management associated with very high-density M9 systems.

M26 can therefore be considered a useful compromise:

M9 → smaller tree, higher density, more intensive management

M26 → larger tree, somewhat lower density, greater vegetative vigor

M9 vs M26: Root Anchorage

This is one of the most important practical differences.

M9 has poor natural anchorage and requires support. Its roots are relatively weak, so a mature tree carrying a heavy crop can become unstable.

M26 has better anchorage than M9, but it should not be treated as a completely freestanding rootstock in all situations.

Extension sources differ somewhat in how strongly they recommend permanent support for M26. Some indicate that M26 may become self-supporting under good conditions after several years, while others recommend support because anchorage is still only moderate.

For a commercial orchard, especially where the soil is shallow, the site is windy or the crop load is high, supporting M26 is the safer approach.

What About Soil?

This is particularly important in Kenya.

M9 performs best where the soil is deep and well drained. It is not a good choice for a site where water regularly sits around the roots.

Its relatively restricted root system also means that the farmer needs to pay close attention to water and nutrient management.

M26 is somewhat more vigorous, but it also has important soil limitations. It is susceptible to collar and crown rot, particularly where drainage is poor.

Therefore, neither M9 nor M26 should be selected simply because a nursery is selling the seedlings.

Before establishing an orchard, evaluate:

soil depth → drainage → pH → fertility → irrigation → cultivar → rootstock → planting density

This sequence is much more reliable than choosing the rootstock first.

M9 vs M26 and Disease Resistance

Neither rootstock should be considered strongly resistant to fire blight.

M9 is highly susceptible to fire blight, while M26 is also susceptible.

M26 also has significant susceptibility to Phytophthora crown/collar rot, particularly where drainage is poor. M9 generally has better tolerance to crown and root rots than M26.

This makes site drainage especially important when considering M26.

Interestingly, modern Geneva rootstocks can offer much better disease resistance than both M9 and M26. For example, Geneva 11 is approximately M26-sized and has substantially better tolerance to fire blight and good resistance to Phytophthora compared with M26.

Where suitable planting material is available, farmers establishing new commercial orchards should therefore not assume that M9 vs M26 are the only two choices.

M9 vs M26 for Kenyan Apple Farmers

The Kenyan decision should be based on the production system.

A farmer with a small piece of land, reliable irrigation, good soil drainage and the ability to install a trellis system may find M9 particularly attractive.

The compact trees make it possible to develop an intensive orchard where pruning, spraying, harvesting and crop management can be done efficiently.

On the other hand, a farmer who wants a moderately compact orchard but does not intend to operate an extremely high-density system may find M26 more practical.

However, M26 should not be selected for poorly drained land simply because it is more vigorous.

Which One Is Better for a Beginner?

For a beginner, I would not automatically say M9.

M9 is an excellent rootstock when the farmer is prepared for an intensive orchard system. But it is less forgiving of poor management.

A farmer who plants M9 without reliable irrigation, support, fertility management and pruning knowledge can quickly discover why dwarfing rootstocks require careful management.

M26 gives somewhat more vegetative capacity and can be easier to manage in a less intensive system, although it still requires good orchard management.

So:

Choose M9 if you want:

A high-density orchard, smaller trees, very early production and high yield efficiency—and you are prepared to provide permanent support and intensive management.

Choose M26 if you want:

A somewhat larger, more vigorous tree with early production, but at a moderate-to-high planting density and with somewhat less extreme size control.

What About Fruit Size?

Rootstock can influence fruit size, although cultivar, crop load, irrigation, nutrition and other management factors also matter.

Some comparative trials have found M9 to produce larger fruit than M26 under certain conditions. Extension research summarizes M26 as generally producing somewhat smaller fruit than M9 in comparative trials.

However, this should not be interpreted as:

M9 = large fruit

M26 = small fruit

Fruit size is controlled by multiple factors. Crop load is particularly important. An overloaded tree can produce smaller fruit regardless of the rootstock.

The Most Important Mistake: Choosing the Rootstock Before the Site

A farmer may see an M9 seedling and think:

“M9 is the best, so I should plant M9.”

That is not necessarily correct.

Rootstock selection should come after understanding the orchard site and production objective.

For example:

Deep, well-drained soil + irrigation + trellis + intensive management + limited land → M9 can make excellent sense.

Moderate-density orchard + greater desired tree vigor + less intensive production system → M26 may be more appropriate.

Poor drainage + high disease pressure → neither should be selected without addressing the underlying site limitations, and alternative rootstocks may deserve consideration.

M9 vs M26: Verdict

If the question is simply “Which is the better rootstock?”, there is no universal winner.

M9 is the better choice for intensive high-density apple production.

It gives stronger size control, very early bearing and excellent yield efficiency. But it requires permanent support and careful management of water, nutrition and crop load.

M26 is the better choice where a farmer wants a somewhat larger and more vigorous tree while retaining early bearing and relatively compact growth.

It provides a useful middle ground, but it still has important weaknesses, particularly susceptibility to fire blight and collar/crown rot.

For a Kenyan farmer establishing an orchard today, I would therefore frame the choice this way:

The important lesson is that M9 and M26 are management tools, not simply different grades of apple seedlings. The right choice depends on the orchard system you are trying to build.

For farmers considering grafted apple seedlings, SeedFarm currently offers grafted apples on M9 rootstock, and its own guidance emphasizes the importance of planning support and orchard management alongside the planting material.

Farmers seeking certified seedlings and expert guidance can contact SeedFarm via website: www.seedfarm.co.ke, Call or WhatsApp: +254712075915, or email: info@seedfarm.co.ke.