Pruning Shrubs Correctly

Q. Attached you will see my 25-year-old bottle brush bush. As you can see, it needs some attention. Can I shape it a bit by trimming it back without harming it? The only trimming I have done is clipping off brown ends each spring (none this year) caused by winter cold. It displays beautiful color for several weeks when the weather warms up.

25 year old Bottle brush shrub

A. Yes but be careful and don’t let the landscape maintenance clods ruin the plant by shearing it with a hedge shears. You may want to consider separation between branches or removing offending branches altogether. It requires either cutting the plant to the ground OR selectively removing some of the older stems. Whether it produces suckers or not will tell you which way to prune it. Either way requires deep pruning cuts, not using a hedge shears.  

         Never use a hedge shears unless you want to replace the shrub in a few years. Hedge shears are for pruning a hedge. That's why the tool used is called a "hedge shears"! If it flowers in the spring, then prune it immediately after it finishes flowering so it has time to grow and produce wood for new flowers.

Formal hedges require quite a bit of work and time. Because they are formal, attention needs to be spent on them once a month. Anything growing "out of place" is cut back with a hedges shears. https://www.hedgesonline.co.uk/formal-hedging

An informal hedge accomplishes the same thing but with far less work. https://laidbackgardener.blog/2016/06/29/a-hedge-for-laidback-gardeners/

            In your case, use a hand pruners and snip three or four branches from each side of the plant, deep inside it, and select where to open it up. Hide your pruning cuts at least 12 to 18 inches inside your shrub. Reach deep inside your shrub. There are several places to prune. Move your hand to each crotch. Ask yourself, "If I were to remove that stem, how would it look?"

           Because it’s so dense on all sides, “cut at a crotch” and remove an entire offending branch or stem. Concentrate on removing stems or branches that are growing down or up. From each section of the shrub remove a stem so the remaining branches are more open and can “breathe”. Remove no more than about ¼ of the branches every three years or so. It will not need more than that.

Pruning with a hedge shears may look okay when the shrub is young, but as it gets older the shrubs older wood needs to be removed. This requires a few well-placed cuts deep inside the shrub.

            When you are finished pruning, the shrub it should look like it was never pruned. That’s the mark of a good pruning job. Who wants to look at an ugly shrub until it grows back? Also spring is the time to apply an iron fertilizer/chelate to the soil to cure the yellowing that occurs on this plant.

Correcting Lemon Mistakes Through Proper Pruning When Young

Q. Your Xtremehorticulture blog is an awesome source of information! I live in Phoenix and question why my ‘Lisbon’ lemon tree is failing after two years. It flowers in the early spring as it should, and produces fruit, albeit, its fruit is nasty and dry. The canopy is about 10% of what it should be, and I suspect sunburn has been choking the plant. I think the tree is a goner and thinking of removing it.

'Lisbon' lemon tree grown in Las Vegas and sun damage to the leaves.

A. Yes, I think your tree may be sunburned. Give it a chance still. At two years of age, you might be able to nurse it back to health if you follow some easy directions.

You live in the northern part of the Sonoran Desert. Las Vegas is in the eastern side of the Mojave Desert. All citrus including ‘Lisbon’ lemon are subtropical; this means the tree, unlike ‘Myers’ lemon, doesn’t survive freezing temperatures very long. And in your case our very strong desert sunlight. As the canopy increases in shade and size, giving more shade to the fruit and the tree itself, the fruit will improve. Guaranteed. Don’t let the fruit overripen before you pick it. That’s a no-no.

This citrus tree was limbed up too soon and the trunk may develop sunburn in hot locations.

You might be able to get away “limbing it up” like in the seaside and Mediterranean area of Portugal, where ‘Lisbon’ lemon probably originated, but it won’t work in the desert Southwest. Leave the tree shrub-like the first few years until it gets established and then slowly limb it up, making sure the trunk and limbs stay shaded, as it gets older.

Citrus with a full canopy but exposed fruit still developed sunburn in Arizona.

Make sure the soil has been amended at the time of planting. This is a subtropical fruit tree and requires more organic matter in the soil than we have in most of our desert soils. I would not surround this tree with rock or rock mulch on the surface of the soil. Instead, use a layer of 3 to 4 inches of wood chips keeping the wood chips away from the trunk the first few years of its life. As the wood chips on the soil surface decompose or rot in the presence of water, it will slowly add “organics” back to the soil. Rock doesn’t do that.

The last thing to consider is planting the tree on the north or east side of your landscape, or at least 3 or 4 feet away from a hot west facing or South facing wall. It may or may not need it but it can help the tree. All fruit trees need about eight hours of sunlight each day, but subtropical trees can do without the 120°F heat common in Phoenix. If they are in good health, they will withstand the desert heat.

How to Prune Texas Rangers the Right Way!

Q. I am new to my home and inherited several Texas ranger bushes. Two of them are on long stems with bushiness only at the top. If I cut these way down, will they bush out, filling around the bottoms of the plant or will I kill it?

Timely Texas ranger pruning allows flowering.

A. I am sure you are not alone with this problem. The short answer is yes, they will grow from the base if cut back. But Texas rangers are slow to grow back after they have been pruned. They are not like oleanders which can grow back quickly as suckers. They don’t sucker well from the base. Instead, they prefer to force their growth on existing stems just below the cuts. It may be necessary to prune all the growth back close to the ground. Leave about 2 inches above the soil or rock for new growth to sucker from the stems.

Pruning Texas ranger with a hedge shears results

            This is a common pruning practice by landscape companies that don’t know what they’re doing. They use hedge shears about twice a year to “shape” these bushes instead of pruning them. Shaping works, but only on hedges. That’s why they are called “hedge shears”.

            If you want to do it yourself then use a sharp lopper or reciprocating saw and cut these big stems back 2 inches above the soil surface and let them sprout from the sides. If there are too many sprouts, pull them off so that only the ones you like remain. It speeds up the growth if you do that. The best time to pull them off is in the spring otherwise you must prune them off. About every second or third year, prune two or three of the largest stems close to the soil surface and let the stems regrow from side sprouts.

Problems with Rat-Tailing Pine Trees

 Rat-tailing a pine tree is removing all of the inside branches from limbs but leaving the newest branches at the end of branches. The short term advantage is that it does allow better air flow through the tree and helps prevent the tree from blowing over. 

However, shallow roots might not support the tree. Shallow roots are because of frequent watering and/or poor soil preparation at the time of planting.

Rat-tailed pine tree. It allows wind to blow through the canopy more easily and helps prevent tree blowover but it causes numerous other problems resulting in limb breakage.

Other problems may result from rat-tailing pine trees.  

Removing interior branches can result in weaker limbs because the branches that were "feeding" these limbs are removed. The branches remaining, those that the ends, continue to feed the limbs resulting in limbs that have less taper and are structurally "weaker" and subject to breakage. Several years may be needed before this is happens. Rat-tailing pine trees may result in less blow over in the short run but eventually it might also result in more limb breakage.

Best Time and How to Prune Ornamental Shrubs

Q. I have some shrubs in my yard that are getting rather scraggly looking.  I was wondering when and how far back I can prune it back in to shape.

Shrubs improperly pruned with a hedge shears. Unfortunately, most people do not recognize bad pruning when they see it and now unfortunately are asking for this kind of pruning.

A. First decide if now is the best time for pruning them or not. You can prune anytime during the winter months. Some plants look better through the winter if they are pruned now. Other plants look fine now but might not look as good if you were to prune them.

As shrubs are pruned more and more into a gumball, in a few years they developed exposed strong stabs at the base.

            Remember, if you prune now you will have to look at them the rest of the winter. If these are flowering shrubs, prune them soon after they finished flowering. If the shrubs do not have ornamental flowers, prune them anytime during the winter.
            The best pruning methods remove the oldest growth from the bottom of the shrub with a lopper or hand shears. Hedge shears for pruning shrubs are, as the name implies, for hedges, not for shrubs.

Properly pruned shrubs require to – 4 cuts at the very bottom to keep it looking good and juvenile.

My Husband Cut Down a Climbing Cactus!

Q. Look what my husband did? He cut my saguaro below the seams before consulting with me.  I know it looked kind of sick (the tree, not my husband), but he cut it. I am going to cut those chunks all the way down. 

Cuts on climbing cactus like these may look bad but they are repairable

A. From your pictures, I don’t think your cactus is a saguaro. I think it is one of the columnar cacti, also called a climbing cactus. Well, it is a setback for the plant because the cuts make it look ugly. The plant doesn’t care, but it is not pleasing to look at.

New growth from just below the cut

            If I’m right, and this is a climbing cactus, those cuts create new growth coming from the ribs just below the cut. The cuts will force new side growth, columns, that continue growing upward.

Propagating columnar cactus

            Another option is to remove all the damaged stems to a couple inches of the ground. Let them “sucker” and regrow below the cut. Remove damaged “arms” entirely if it looks bad. Cut these removed columns or “arms” into 12 inches long segments for planting. Put them in the shade for one to two weeks to heal the cuts before planting.

            After two weeks, plant them in soil amended with compost (not upside down!) with about one third of the 12 inches stuck in the ground. Stake to hold them upright until they grow roots and they don’t fall over. Water every 2 to 3 weeks so that the soil is dry between irrigations.

            Let the columns which weren’t cut continue to grow but “lean” against something upright. These cacti will get tall if they don’t freeze back during a very cold winter.

Many of the columnar cacti are also called climbing cacti. They get so tall they can fall over if they don't lean on something. Many of these cacti do not handle intense sunlight very well in the desert. In response to sunburn to the columns, these cacti will grow new site shoots and propagate themselves.

            In your picture, some columns appeared to be damaged by intense sunlight. This damage was forcing a lot of new side growth from the columns. This cactus will grow much better with amended soil and put in a location where it gets some shade from the late afternoon sun. Now might be a good time to move it to a new location and let it “lean”.

Elm Tree Growth After Bad Pruning a Possible Liability

Q. Could you give some advice on this elm tree. It is about 40-45 years old. My father topped it (it is in SE Oregon).  I think it may need to be cut down, however if possible to improve it, that would be what I would like. The branches are so spindly I think they will break easily.  Also, any idea how much longer it can survive?

Elm tree in SE Oregon, probably Chinese elm.

A. Most of these remaining elm trees are Chinese elm and considered “trashed trees” as far as their landscape value in urban areas is concerned. Yours appears to be in a rural area. In rural areas, “trashed trees” can be still valuable.

            Your tree has grown back for several years from a bad pruning job so I would leave it alone. One of the big problems with bad pruning jobs is limb breakage because of how the tree grows back after bad cuts. This can be a liability problem.

            If you’ve had strong winds through there with no limb breakage then I would be less concerned. Otherwise, have a certified arborist come through and do an evaluation of the tree.

            Personally, I don’t think a tree like that’s worth it. If you have concerns about its looks or liability, I would have it removed and put in something else.

Normal for Vertical Limbs to Become Horizontal

Q.  My Seville orange tree has been growing in my yard for 20+ years. About a month ago, I noticed one of the branches that grew straight up is now parallel to the ground. Any idea what caused this?

 

Pomegranate growth is a little different from citrus growth. But there are similarities. According to the owner of this tree, it has not yet flowered and fruited. Its branches are vertical. After it begins fruiting the weight of the fruit will pull the branches to a horizontal position.

A. The reason upright limbs of fruit trees with large fruit become horizontal is from the weight of the fruit. The fruit tree which demonstrates this the best is pomegranate.

This orange tree has not yet produced fruit. Its major branches are vertical.

            The upright shoots of pomegranate bend nearly horizontal after they flower and bear fruit. The weight of the fruit bends the branches downward. To a lesser degree we see this in ornamental trees and nut trees as well as they get older.

This fifteen-year-old pomegranate tree has produced an abundance of heavy fruit. The fruit has waited the branches and open the canopy. Opening the canopy allows more sunlight to enter it and the tree produces more fruit. Relate this back to natural selection and evolution.

            In these cases, the weight of the branch as it gets longer and heavier begins to bend the branch into a more horizontal position. Often times young trees are described as being "upright or semi upright" while the mature forms of the tree may be called vase shaped or even round.

How to Care for Lilacs in the Desert

Q. My lilacs have bloomed and the flowers are gone. Is now the time to prune or do nothing? How do you prune or care for the lilacs.

Lilac planted in rock mulch with brown scorched leaves

Shrub pruned with heading cuts close to the ground

A. Most people don't know that low-chill varieties of common lilac will grow here as well as the Persian lilacs. Plant them in plenty of sunlight but in places which avoid the hot afternoon sun. All lilacs must be planted in a composted soil with a wood chip mulch. Rock mulch will not work.

Low-chill varieties do not need as much low temperatures to produce flowers. Lilacs that are not low chill will not produce as many flowers in our warm winter climate. Some plants require long periods of time when temperatures are cold so that flowers will be produced the next year.

Persian lilac may be a better choice for our climate and in smaller yards than common lilac. Persian lilacs are smaller in stature than common lilac, with smaller flower clusters and a lower winter chill requirement.

Hopefully local nurseries and garden centers that sell lilacs for our climate are selecting low-chill types such as an old time favorite here called "Lavender Lady". I believe this, along with "Angel White" were the first low chill lilacs available that would grow in the desert Southwest. Many of these low-chill varieties are referred to as the “Descanso Hybrids”.

Lilacs are not desert plants so they require lots of compost mixed in the soil at the time of planting with the soil covered in wood chips that decay over time. They should not be in rock mulch.

A very nice article appeared in Sunset Magazine and you can read it here http://www.sunset.com/garden/flowers-plants/mild-climate-lilacs

As with any seasonal flowering shrub or tree the best time to prune them is soon after flowering. If pruned later than this, the flowers for next year may not be produced.

First, remove the dead flowers before they form seeds by cutting them off at the base. Next, if needed, cut back branches or stems.

To increase the number of flowers you should increase the number of new branches it produces. Use a "heading cut". This type of cut is made somewhere along the length of the branch, usually just above a leaf on the outside of the branch.

Heading cuts grow three or four new shoots for every one that is cut that is made. This is an excellent way to make a shrub denser with more flowers.

If the shrub is getting too large, remove one third of all the longest stems back to within a couple of inches above ground. New stems will grow from just below these cuts.

A radical way of pruning this plant is to totally cut it off just above the soil surface. With plenty of water and some fertilizer new shoots will grow from these very short stubs resulting in an all-new plant. This is pretty radical but if the plant is overgrown with lots of wood showing, this may be your only alternative.

Remember, after pruning give it plenty of water and fertilize it with an all-purpose fertilizer.

Brown Center of Pampas Grass Common

Q. A few weeks ago I cut my ornamental pampas grass down, removing all last year’s dead growth. As the new growth is starting, I noticed a peculiar brown, circular pattern in the center that hasn't happened in the past. The new growth is coming along fine; nice and green, and a couple inches taller. Just nothing in the center.

Brown Center of pruned pampas grass

A. This brown center is common to many ornamental grasses as they get older. When the plant is very young and juvenile the entire plant is green, even the center.

As these plants get larger, they grow from outside shoots, or tillers, that make the plant larger in diameter. Each year this clump of grass gets larger and larger with the brown interior getting larger as well.

When these ornamental grasses get larger, the entire clump is dug up and divided into several smaller clumps. This propagation technique is called “division”. The brown portion of the plant is removed and the smaller plants are replanted or containerized and sold as a juvenile plants.

However, the new growth of your plant will cover up the dead interior and I don't think you will notice it anymore until you cut back again. 

Boxwood Hedge Slower to Recover From Pruning Damage Than Rosemary

Q. I have a neighbor concerned about his rosemary and boxwood hedges. The foliage has been falling off. Landscapers recommend he cut them to the ground to get them to recover but he opted to cut them back halfway instead. Now there is a lot of bare wood exposed with no leaves. What should he do to help them recover?

Should a License Be Required to Carry a Hedge Shears?

What was not forseen in the advent of desert landscaping was the dramatic change in pruning techniques brought in by the landscape industry. Hand pruners and loppers were gone. Hedge shears were in.

Still Afraid to Prune Your Lantana?

You may have either the purple lantana or the multi-colored lantana. Most of it died back during the winter. But where to cut? What if I cut it back too far. Will I kill it? Even in February you still have time.

Not Too Late to Trim and Fertilize Lantana

We generally grow two types of lantana in the landscapes in southern Nevada; the purple one and the one that is multi-colored, usually with some yellow and rose or pink flowers. Both are handled about the same way in watering, pruning and fertilizing.

Remove Suckers Coming From Rootstock on Loquat

Not sure if I should remove growth below the graft from a Loquat tree.

Acacia Damaged by Low Temperatures and How to Remove Limbs

Q. Any advice on Acacia trees would be great.  These trees took a hit when the temps dropped to the 20's in December.  I see new growth, but mostly on the suckers.  Should I leave the suckers there or remove them? What is the best thing to do to help these trees recover?

A. This is more complicated. First you will remove any wood you know is dead. By now (June), any part of the tree which is still alive should have thrown out some growth. Remove any limbs that are dead (no growth coming from them) by cutting at point of attachment to another limb or the trunk.  You should not leave any stubs when you are done.

            If the limb is large and heavy, you should remove it by either removing sections of the limb at a time that are manageable or use a technique that we sometimes call the 1-2-3 method. This is demonstrated pretty good on removing a limb on wikihow. Here is our sequence of cuts at the Orchard.

Cut number 1 is made upward about a foot from where the final cut will be made.

The second cut is made downward a few inches away and to the outside of the first upward cut.

The weight of the large limb causes the limb to begin splitting when it falls. The split occurs from the outside second cut to the upward first cut. The prevents the limb from splitting down the side of the branch and into the trunk.

This is a look at the limb that has split from the branch and now lies on the ground.

The third and final cut in the 1-2-3 limb removal sequence is made at the proper distance from the trunk. This leaves the trunk/limb "shoulder" in place and finds the balance between the smallest cut possible and not leaving a stub. The cut is left to heal on its own and no coating or sealer is used.

 

This is a different tree but gives you an idea of what the "shoulder" looks like and where it might be located on a much smaller limb.

 Next, remove any broken branches. They will not repair themselves. Remove any wild or “sucker” growth. This type of growth usually has weak attachment to the trunk and not support itself in years to come. Remove any growth coming from the trunk that is not high enough in the future.

            This growth will not get any higher and as it gets bigger will “sag” or bend downward perhaps into places where you can bang your head. Remove these by making a “flesh cut” in other words remove it all and don’t leave a stub.

            Finally thin out the remaining branches so that any dead wood is removed (again by making “thinning cut” which is the same as in the third sentence, removing it at a point of attachment without leaving a stub.) Try to have the remaining branches going in different directions to help balance the crown visually.

            I hope this helps. By the way, I would do any major limb removal next early spring after the worst temperatures have passed. Minor cuts (with a hand shears) can be done any time.

Mesquite Bushes Can Be Trained to a Tree

Q. I grew up in a part of Texas where mesquites were bushes not trees.  We have a small backyard here in Vegas with two mesquite trees in it; one large one and one slender one. There is little or no green on them, just wood. There are so many woody branches I am wondering if they will ever give us shade.  Would you please educate me on this?

Native honey mesquite growing in the Mojave Desert just outside of Las Vegas, NV

A. The Texas mesquite or honey mesquite is a shrub that we prune into a tree form. The plant grows well here but is usually not a preferred type of mesquite because of its long thorns. There are improved types of mesquites that are usually preferred.

            With a little bit of care when they are young they can be trained into a tree form.

            In our climate many mesquites drop their leaves in winter and so are considered deciduous to semi evergreen due to winter cold. In warmer climates they tend to stay evergreen during the winter unless there is a cold spell. 

One of the ornamental mesquites in the nursery trade, claimed to be thornless, showing dense canopy and shade, a sign of abundant water.

            We consider our local mesquite to be a riparian species of plant. In other words it puts on growth when water is available and slows down when water is not. When mesquite trees are watered frequently they can put on large amounts of spindly growth, perhaps 8 feet or more each year.

            Mesquite are normally very deep rooted plants in the wild. Being deep-rooted gives them the capability of avoiding long periods of time without water. For this reason they can be very drought tolerant if they have rooted deeply.

Native mesquite growing in the Sonoran Desert near Jerez, Mex, demonstrating sinker roots tapping into deep water from a nearby river.

             If mesquite trees are watered too often, their roots will tend to be shallow and not deep-rooted, a frequent problem in over-irrigated landscapes. They also tend to put on a lot of wood because of frequent irrigations.

            Mesquite trees handle pruning very well and their growth is very adaptable to landscape management. They do well with light fertilizer applications annually. They should be grouped with other desert plants for irrigation purposes.

            After training these plants into a tree form they do not require a lot of pruning. In fact heavy pruning just encourages a lot of new growth. I would remove lower branches just high enough to allow traffic to pass under them.

            Frequent irrigations will cause these plants to be lush and provide dense shade. Watering less often will cause them to become more open and provide lighter shade. Remove branches that are crossing or growing too close together.

            Limbs would be removed at their point of origin, not by hedging or simply cutting them back.