Pruning and Trimming an Oak Tree

For a lot of people, trimming and pruning an oak tree is a daunting task. They don’t know which branches to cut off or what to do with the ones they want to keep. 

The best way to handle this project is by deciding on your goal for the tree’s shape before you start cutting anything at all. If you’re looking for more of a natural look, then just trim back any branches that are too long or crossing each other, so there is plenty of space in between each branch. 

It may be better for those who prefer a more structured appearance if one cuts some branches away altogether and chooses different replacements instead. These tips will help anyone tackle their own oak tree trimming project without feeling overwhelmed by it!

California oak, or live oak, is a beautiful, tall tree that benefits from pruning for growth and maintenance. This variety of oak is different than other oaks in that it stays green throughout the year. 

There are specific times of the year for pruning that are less stressful for the California oak. Choosing the correct time keeps this variety of oak trees attractive and healthy in the home landscape.

Pruning Methods

Prune the branches with the three-cut method that maintains the branch collar — the swollen area at the branch’s base. Make the first cut on the bottom of the branch about 18 inches away from the branch collar. 

Cut the branch halfway through from the bottom to the centre. Then, make the second cut on the top side of the branch about 1 inch away from the first cut. Cut through the branch during the second cut until the branch falls from the tree.

Make the third cut next to the branch collar to remove the remaining branch section while leaving the collar intact. Removing the branch collar makes a large wound on the tree and promotes decay. Next, trim a portion of a branch by cutting it about 1/4 inch above the branch bud that is facing away from the trunk to force growth outward.

Optimal Time to Prune

California oak trees have the best results when pruned during the coldest winter months of the year before the tree begins to bud and generate new leaves. The tree is growing throughout the year, but not aggressively during these winter months. 

The reduction is growth means there is less risk of insects or disease entering and damaging the tree from the open pruning wound.

Winter Pruning

Prune the crown of the California oak during the winter months each year for three years after planting. Remove low-growing branches to force the crown into a strong and attractive arching shape. 

Remove all branches with a narrow crotch to increase branch strength in those branches that remain. Prune the tree while it is young and the branches are low enough to reach safely.

Pruning During Other Times of the Year

During the hottest time of the year, pruning the California oak from mid-summer to late summer is an option if the late winter pruning time frame was missed. Complete the same type of pruning during this period as you would in late winter. 

It is important to avoid pruning during the spring when new buds and leaves are forming or in the fall when the tree is shedding dead leaves. Pruning during these times is stressful to the California oak and may reduce tree health.

How to Trim an Oak Tree without Killing It


Oak trees are indeed beautiful to look at. However, it requires work in order to keep it healthy and strong. Hence, trimming an oak tree should be done from time to time. However, trimming done the wrong way can kill your oak tree instead. So here, we would be teaching you the proper way of trimming an oak tree without killing it.

Consider Trimming Them During The Winter Months

If the oak tree you have at home is still young, you need to consider trimming them during the winter months. That way, it would be able to recover from it’s wounds faster. When trimming them, it is also very important for you to consider the growing habits of your tree.

Clean The Clipper And The Blade Of The Saw

Before you start trimming your oak tree, you first need to clean the tools and equipment you would need. After that, you can simply use clean water with a little bit of household bleach to disinfect it. First, of course, you need to make sure that it is rinse well and that there is no household bleach residue left in it. 

You also need to let it dry before you start using it. Also, to prevent the spread of diseases between the oak trees that you plan to trim, you need to wash the clipper, and the blade of the saw before and after you trim an oak tree.

The Branches That You Should Remove

For oak trees that have been newly planted, you need to trim only its dead and broken branches. It is not suggested for you to trim your tree to shape. Instead, wait for about 2-3 years before you can start shaping it. 

That way, you can prevent yourself from killing your oak tree. On the other hand, for a mature oak tree, you need to remove the branches growing towards the centre of the crown. With that, airflow can be ensured. 

Apart from that, you also need to remove the branches that are rubbing with each other, for this is one way of preventing wounds on the branches. As we all know, wounds serves as an entry point to diseases, and in order for you to keep your oak tree healthy, you need to do whatever you can to prevent diseases from spreading to them.

No matter how much you wanted to keep your oak tree healthy, you also need to ensure your safety while doing it, and it is a known fact that oak trees grow massively tall. Hence, there might be branches that you would want to remove, but you are unable to reach them.

In such a case, it would be best for you to seek for help from an expert who has already been in the oak tree trimming business for years already. With that, both you and your oak tree are kept safe and protected at the same time.

When Is the Right Time to Trim Oak Trees?

Do you know the proper window of opportunity to trim oak trees? Unfortunately, too many tree novices mistakenly believe you can prune tree branches all year long. While this is technically true—after all, a plant won’t stop you—it could hurt the tree. In addition, cutting back live branches is an art and requires an understanding of arboriculture. So before you pick up your pair of heavy-duty loppers, make sure it’s the right time to prune your oaks.

Spend Summer Climbing Instead of Trimming

There’s nothing better than spending your days outdoors during the summer. Can you picture the kids climbing the trees while you sip on lemonade? And while your oak trees may also flourish during this beautiful, hot season, you should put your tree trimmer back in the shed.

Contrary to what many homeowners assume, summer is the worst time of year to cut off oak branches. Instead, it’s best to prune from late fall to early spring—November 1 to March 31, to be precise. These are the months when oak trees are less vulnerable to disease and infestations.

The Risk of Summertime Oak Tree Trimming

Any time you cut into a branch, it leaves a wound on the tree. Now, think about what happens if you cut your arm. A fresh injury is more apt to get infected, which sometimes leads to serious complications. This same theory is true when it comes to oak trees, and the consequences are often dire.

Oak trees are susceptible to a dangerous fungal disease called oak wilt. Even though oaks are strong and mighty, this fungus can take down even the most robust tree. It most commonly occurs whenever someone prunes a tree during the wrong time of year, also known as summertime.

Tiny sap beetles spread oak wilt from tree to tree, and they are the most active from April to August. These unwelcome visitors seek out oaks with fresh prune cuts, where they leave behind this fast-spreading fungus. Unfortunately, oak wilt is often fatal.

Oak Tree Pruning Ordinances

Even when pruning season finally rolls around, you can’t just start chopping away. Many cities have tree ordinances in place to protect certain tree species—and oaks often fall under these laws.

Pruning a large oak tree without the right paperwork may end up costing you. Always speak with a tree specialist to make sure you don’t need to obtain any permits. These rules not only save the trees but they also protect the community.

Local Oak Tree Specialists

Massive oak trees are a staple in any yard. Not do the large canopies provide plenty of shade, but these majestic trees also add a ton of curb appeal. However, if you own an oak, you’ll need to trim it once every 2-3 years. Properly pruned trees live longer, healthier lives.

Pruning trees is a dangerous job. One wrong move could have lasting consequences. Instead of attempting this tedious project yourself, let experts do it for you. We are the local tree experts. Our team specialises in tree trimming and removal. Contact us for a free quote to trim oak trees on your property.

Care of Native Oaks.Best Management Practices.Watering Oaks

Native oaks do not normally need water. However, during dry winters, early spring deep watering can be applied from March through May. The root protection zone is 1.5 times larger than the area from the trunk to the drip line. Therefore, disturbances in the root protection zone should be minimised. 

Only drought-tolerant plants that require no summer water should be planted around oaks. Plants should be planted no closer than six feet from the base of the tree. Avoid planting grasses, ivy, ferns, or any other vegetation that needs summer watering. Do not plant Sudden Oak Death hosts such as camellia, rhododendron, or azaleas near oaks. 

Other types of ground cover can be used to landscape beneath oaks. Cobbles, gravel, and wood chips are good examples. Mulching under oaks with organic material is beneficial to oaks. Allowing the fallen leaves to accumulate under oaks creates a natural mulch layer.

Trenching under oaks for the installation of utilities can kill the oak if large roots are cut. If utilities must impinge on the root protection zone, the trench should be dug by hand to avoid roots larger than two inches. Utilities should be bored through the ground at least three feet below the surface to ensure that the roots are not damaged. Changes to the grade with fills or excavation can severely damage the roots. 

It is best to prune oaks when they are dormant. Live oaks, which retain their leaves year-round, are dormant July thru October. Deciduous oaks, which lose their leaves in winter, should be pruned during the winter. Oaks do not tolerate severe pruning and can be killed if topped or severely pruned. Never prune out more than 15% of the greenwood in a single pruning and avoid large wounds. 

The most serious diseases of native oaks are Sudden Oak Death, Phytophthora root and crown rot, and Armillaria root rot (the oak root rot fungus). Phytophthora and Armillaria are favoured by summer irrigation or excess irrigation. 

Numerous insects live on oaks but rarely cause significant damage. Small wasps cause galls on leaves and twigs where they lay their eggs but are insignificant and do not harm the tree. The oak moth can defoliate oaks when populations are high, and treatment may be required. The oak twig girdler can cause numerous patches of dead leaves but does not adversely affect the trees health. Wood bores are common in the trunks of coast live oaks, but they too do not adversely affect the trees health. 

Mature oaks need little or no supplemental fertilisation. However, light fertilisation may be needed in landscaped situations to replace nutrients supplied by leaves that normally accumulate under an oak. 

Guidelines For The Care Of Native Oaks And Prevention Of Sudden Oak Death 


What is Sudden Oak Death? Sudden Oak Death (SOD) is a disease caused by Phytophthora ramorum, a new species that has killed large numbers of oaks and tanoaks in some central coastal areas. The disease has now been found on camellias at some nurseries. 

Temperature and humidity are limiting factors for the disease, so the potential of SOD becoming established in coastal areas is greater than inland areas. Our climatic conditions will likely prevent the disease from becoming established in natural or landscaped areas.

How do you recognise Sudden Oak Death? If any susceptible oak species grow on your property, look for the following symptoms: Bleeding or seeping of a dark viscous substance from the trunk or large branches. Reddish or tan-white fine, boring beetle dust resulting from bark and ambrosia beetles tunnelling into the bark and/or wood. 

The appearance of hard, golf-ball-size, dome-shaped fungal fruiting bodies is green when new and later turn charcoal black called Hypoxylon. Laboratory culturing is the only way to confirm whether asymptomatic oak is infected with SOD. 

Is Sudden Oak Death the only cause of oak mortality?  No. Many other pathogens can also kill oaks. For example, Phytophthora root rot fungus (Phytophthora cinnamomi) and oak root fungus (Armillaria mellea) are common in landscapes and gardens. In addition to pests and pathogens, improper cultural practices such as soil compaction, root pruning, overwatering and herbicide use may contribute to the death of oak trees. 

Are all oak species susceptible to Sudden Oak Death?  At this time, three oak species, California coast live oak (Quercus agrifolia), California black oak (Quercus kelloggii), and Shreve oak (Quercus parvula var. shrevei), live canyon oak (Q. chrysolepis) and the closely related tanoak (Lithocarpus densiflorus) have been found to be killed by the new Phytophthora species. 

Other oaks, such as valley oak (Quercus lobata), blue oak (Quercus douglasii) and many introduced ornamental oaks, have not yet tested positive for the new Phytophthora. However, two oak species native to the east coast, northern red oak (Q. rubra) and southern red oak (Q. falcata) have been diagnosed with SOD in England. 

How does Sudden Oak Death spread? It is not currently known how the P. ramorum spreads from an infected tree to a healthy tree. Most species of Phytophthora are spread in soil and water or infected plant material. A few species are also known to be airborne. The new Phytophthora species can reproduce rapidly on the leaf surface of hosts such as bay laurel and madrone. These hosts may be important in that they allow for the build-up of Phytophthora spores and therefore serve as a source of infection. 

What can you do for oaks that do not have symptoms of Sudden Oak Death? Focus on maintaining oak health through proper cultural practices. Avoid disturbance of the root zone. Avoid frequent irrigation. Minimise injuries to the stem and lower limbs. Prune oaks when they are dormant. 

Limit pruning to the dead, dying, and structurally unsound branches. What can you do if trees are infected? Monitor oaks in urban settings for the bleeding symptom year-round. If the bleeding symptom is detected, consult with a certified arborist or county agricultural department to find out whether the cause is the new Phytophthora species.

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