Granny Smith apple trees are one of the most popular types of apple tree grown in North America because of their long harvesting season and the sweet, tart flavor of the apples. But if you’re planning to grow a Granny Smith apple tree, it’s important to know how big it could potentially get in order to understand the kind of space you’ll need for the tree. Let’s take a look at how big a Granny Smith apple tree can grow.
Grafted Granny Smith apple trees tend to get the biggest, and these sometimes reach 20 to 30 feet tall when they reach maturity. However, their size will also be partially dependent on environmental factors. If they’re grown in a place that gets plenty of moisture and sun, they can be expected to be at the higher end of the size range. Trees grown in more challenging conditions might tend to be at the lower end.
The width of the tree can vary widely. Most Granny Smith apple trees grown in a home garden range in width from about 10 to 20 feet, depending on the amount of pruning, amount of exposure to sun and air, and the type of soils in which the tree is planted. Trees grown in extremely fertile and well-draining soils tend to be on the larger side when it comes to their width.
At first, a Granny Smith apple tree may grow very slowly, taking 2 to 3 years for its height and width to develop substantially. But when it enters its adult phase at around 5 or 6 years old, its growth rate can become more rapid, causing it to reach its potential size quicker.
The shape of the tree can also factor into its size, with standard trees tending to get significantly larger than espalier or stepover trees. Granny Smith apple trees can also be trained to grow as part of a multi-leader configuration, such as with a central leader and some scaffold branches that divide the task of bearing fruit and carrying large amounts of foliage.
Newly planted Granny Smith apple trees should have their central stem headed back to its first lateral branch. This should be done as soon as they’re planted, as it encourages the tree to develop more growth from the lower portions. Heading back late can stunt the height of the tree.
It’s important to remember that eventual size can’t be predicted for sure when it comes to Granny Smith apple trees. They’re organic beings, and there are too many variables that can influence the tree’s eventual size and shape.
Soil Type
Soil type plays a major role when it comes to the eventual size of a Granny Smith apple tree. Soils that are too sandy might not be able to hold enough nutrient and water for a larger-sized tree. On the other hand, if the soil is too clay-based or acidic, then the plant can struggle to absorb the vital nutrients for healthy growth.
When soil is too compacted, the tree might experience stunted growth because of an inability to penetrate the soil for fanning out its roots. It’s essential that you select the right soil type for your Granny Smith apple tree from the start or amend an existing soil to make it more suited for the tree.
It is also important to ensure that the soil drains properly. Poor drainage can cause the roots to rot and the leaves to wither. Conversely, overdraining can lead to fewer nutrients being available to the tree, negatively impacting its eventual size.
Granny Smith apple trees perform best in soils that have a pH between 6 and 7, though they can sometimes tolerate soils on the more acidic side, depending on their variety. The best soils tend to be slightly alkaline and should have light, airy elements and lots of organic matter.
Fertilizing
Fertilizing is an important part of growing large, healthy Granny Smith apple trees. Applying fertilizers helps to provide the nutrients the tree needs to reach its potential size. A balanced fertilizer can encourage deep rooting, and this in turn promotes a larger and healthier tree.
Organic fertilizers such as compost, manure or fish emulsion are great for the long-term growth of Granny Smith apple trees. In addition, a liquid fertilizer should be applied during the growing season for best results. Nitrogen fertilizer should be used to promote growth and increase foliage, while potassium and phosphorous should be used to promote bloom and fruiting.
It’s important to remember that fertilizer is needed only when plants are actively growing, which is generally during the spring and summer when the weather is warm. Some trees benefit from semi-annual fertilizing and this should start when the tree is in the dormant period and stop once the growing period begins.
In addition, soil and foliage tests should be conducted regularly, particularly if you notice decreased vegetation. These tests can provide insight into what, if any, adjustments need to be made to the soil and fertilization regime.
Pruning
Pruning is essential for achieving a larger Granny Smith apple tree. Pruning can help promote health and vigorous growth, and it can also help shape the tree’s eventual size by keeping its limbs in check. This can be done by pruning away any excess growth or branches that are at the wrong angle.
Care should be taken to cut off damaged or unproductive branches. This should be done by cutting just above a node, and the pruning should be done so that the angle of the cut encourages new growth in the right direction. Pruning can be done both in the dormant and growing season, though it’s generally best to avoid winter pruning, as this can cause the tree to suffer.
In order to help direct the growth of the tree in a way that will encourage a larger size, some Granny Smith apple trees can have up to four leaders. This is preferable to more traditional one-leader-style trees, as it evenly distributes the load and encourages it to grow in a more formed, stable way with better access to space and light.
When pruning, it’s important to use tools that are in good shape, as equipment that’s damaged or has long-unused blades can cause damage to the tree. In addition, protective gear such as gloves should be worn, as pruning showers the area with wood chips.
Watering
Watering plays an important role in promoting strong growth and a larger Granny Smith apple tree. Newly planted trees generally need to be watered daily for some weeks before the weather cools down. After that, the tree should get regular waterings, depending on the soil and environmental conditions.
A good test to see if the tree needs to be watered is to stick in a finger or soil moisture measurement meter. If the top few inches of soil are dry, then the tree should get some more water.
Water should be directed at the root zone of the tree, which is usually about two to four inches beyond the tree’s trunk. This helps to encourage deeper rooting and thus a larger tree. Shallow watering can lead to smaller trees as the roots rely on frequent waterings.
It’s important to avoid over-watering the tree. Too much water can cause the roots to rot, leading to the eventual demise of the tree. It’s better to err on the side of caution and water the tree less often but deeply when it’s needed.
Purchasing
The size of the tree you purchase will also affect its eventual size. Granny Smith apple trees that are nursery grown and bought in larger sizes tend to quickly reach their potential height and width in comparison to their younger counterparts. It’s important to take into account the environment in which the tree will eventually be planted in order to buy a tree that’s fit for that location.
Granny Smith apple trees come in different varieties, and each variety has its own potential size. For example, ‘Cox’s Orange Pippin’ is a standard tree and will eventually reach a height and width of between 12 and 18 feet when mature, while ‘Bramley’s Seedling’ will reach only about 10 feet in height and 8 feet in width.
Granny Smith apple trees that have been grafted have the potential to reach the largest sizes. Dwarf varieties are more suitable for smaller spaces and can reach a maximum height of between 6 and 12 feet.
When purchasing a tree, it’s important to investigate which rootstock the tree is grown on. This can make a significant difference to the eventual size that the tree will reach.
