A primer for pruning roses

Posted on 02/09/2021 4:06 pm  

Master Rosarian Sue Streeper teaches how to prune a hybrid tea rose at the Balboa Park pruning workshop.  (Rita Perwich)

What does “directing traffic” have to do with rose pruning? This is the phrase master rosarian Sue Streeper uses when she teaches her pruning workshop in Balboa Park. When we prune our roses, we guide the direction of their growth, their shape, height and size, the quality of their blooms and their health and vigor for the coming year.

We direct them to rest and then become productive.

Our plants naturally slow their growth and channel sugars to their roots as the days get shorter. They will tap into this stored energy for their initial stem and leaf growth in the new growing season. Pruning provides them with a rest and a restorative period.

To avoid setting our plants back, we must finish our pruning in San Diego by mid-February before our roses start to leaf out. We start at the base of the plant and prune out dead, damaged, diseased and old unproductive canes by sawing down at the base of the plant (known as the bud union on a grafted plant). This encourages and opens up space for the growth of basal breaks, which will become the new and more productive canes.

We direct the shape and size of the plant.

Roses are subject to a growth phenomenon called apical dominance. A plant hormone called auxin in the tip (apex) of the cane suppresses growth from lateral buds further down the cane. Removal of the tip through pruning allows the lateral buds to temporarily grow. This results in a fuller plant with more blooms on the canes.

Our next consideration in shaping our plant is to control disease. In order to minimize fungal problems we open up the center of the plant to air circulation and light. There is a bud eye at every leaflet set. We “direct traffic” by making our cuts one-quarter of an inch above a bud eye that is outward facing. This prompts the rose to grow in that outward direction and away from its center.

How much to prune? There are general guidelines on how much to prune, depending on the class of rose and the age of the plant. In San Diego, usually we do not prune more than one-third to one-half off our hybrid teas. With floribundas, polyanthas, shrub roses and minifloras and miniatures, we generally cut back only one-quarter of the height of the plant and we do not remove as many canes and as much growth as we do on the hybrid teas. All the canes on the bush do not have to be cut at the same height. Younger plants should be pruned very lightly.

Old garden roses that bloom only once need just a light grooming after their flowering has finished, and very little pruning in January other than the removal of old and dead growth.

Climbing roses are pruned very differently from other roses. The main canes are not pruned unless they are dead or damaged. Climbers bloom off lateral shoots, so this is a good time to train new, flexible canes horizontally as much as possible in order to encourage lateral growth. Your cuts are ma

de at the third or fourth bud eye on each of the lateral shoots growing off the main canes.

A hybrid tea rose after it has been pruned. (Rita Perwich)

We direct the quality and size of the blooms.

On hybrid teas, we want one large bloom per stem, so after the described basic clean-out of dead, damaged and twiggy growth, we generally get rid of stem-on-stems, also known as “doglegs,” and then we cut back to an outside bud eye on a cane that is thick enough to support the desired future bloom.

We can leave some of these branching doglegs on floribundas and shrubs, but we do need to get to a stem diameter that will support the quality of blooms or cluster of blooms we want. Next, we look for an outward-facing bud eye to make our pruning cut.

We direct their health.

We already cut out the dead, diseased and damaged canes, but if we notice that the pith in the center of an otherwise healthy-looking cane is brown, we keep pruning down the cane until we reach creamy white, healthy tissue. Pruning at the start of the new year has the added bonus of ridding the garden of last year’s problems. After pruning our roses, we strip all remaining leaves and we dispose of all canes and clippings to get rid of dormant spores of fungi and over-wintering pests.

If we decide to dormant spray with horticultural oil or insecticidal soap, this must be done immediately after pruning and before any bud eyes develop, as the spray can harm them.

Direction is best with the right tools.

Pruning is made a lot easier when we have the right tools. We need a sharp pair of bypass pruners, sturdy gauntlet gloves, a small pruning saw to make clean, flush cuts and a sharp pair of loppers to cut through thicker canes. It is a good idea to wear a long-sleeved shirt.

When we are finished, we need a rake to clean around the base of the roses to remove all leaves and clippings from the garden.

Hands-on direction

Pruning roses is best learned by watching the procedure and then practicing what you learned while being watched. Bring your gloves and pruners and attend the annual hands-on pruning workshop presented by consulting rosarians of the San Diego Rose Society at the Inez Grant Parker Memorial Rose Garden in Balboa Park. This year, the free event is on Saturday, Jan. 11, from 9:15 a.m. to noon.

Perwich is a member of the San Diego Rose Society, a Consulting Rosarian and a Master Gardener with UC Cooperative Extension.


Posted on 07/30/2019 12:00 am  

Smart irrigation systems are really smart. And as sportsturf managers, we should embrace this fairly new technology and use it to full capability. Saving water is critical for me in Weston, MA and that was the driving force behind retrofitting our 13 controllers/systems across our Town a few years ago. Even if you don’t pay for your water, being judicial with your water usage is critical in having high performing sports fields.

Besides water savings, there are many benefits to these systems whether it’s retrofitting old systems or installing new. Turf managers can save labor and time with these systems as well. With “old fashioned” systems, you need to walk, or in my case drive through town and open each controller and program them. This might be a daily or weekly occurrence. Well, we all have smartphones, so wouldn’t it be great to sit on your couch at home and set the controllers? How about turning them off when you see the thunderstorm rolling through on the radar. Smart systems are internet-based and can be manipulated anywhere you can connect to them.

Retrofit Doesn’t Help Poor Design

Some things to consider when looking at retrofitting your systems: These systems do not help poorly designed systems. They will not correct poor head placement, poor flow, poor pressure or aging infrastructure. Infrastructure should be in good working order before embarking on installing these systems.

Something to consider if your systems are not preforming as well as you would like: have one site or multiple sites assessed by a professional irrigation consultant. They will run through your system from the point of connection to the last head of your system and provide you with a site assessment. We did ours one year prior to the central control system upgrades. A tangible report is an easy sell to your administrator or boss to show the good and the bad of your irrigation systems. This allowed us to see all our deficiencies and provided us with a list of items that should be fixed right away, like broken heads and stuck valves, and longer-range items like adding a pump to a system to increase pressure.

Maybe you only have one field to control. These systems, through all the major manufacturers, have WiFi systems that can instantly turn your old controller to a new “high tech” system at relatively low cost.

Flow Control is Key

I think the heart to any smart system is having flow control. Managing the flow of your system is critical. Knowing how much water the system puts out every day or night is great information. Using flow to your advantage can help reduce watering times. This in turn reduces leaf wetness. Each system has a designed flow or optimum flow. Let’s say for example that is 100 gallons per minute. Flow on each zone of your system might be different, but the controller can combine multiple zones that equal to your designed flow. Instead of running one zone at a time, this might let your system run up to three zones or more at one time, reducing watering times.

My system sends me two emails each morning at 6:30 am: a run time pdf, where I can see each of my 14 sites, including what zones ran, which didn’t, and total amount of water per field. The second email has alarms and warnings.Maybe I had a stuck open solenoid on a field. The system will understand that the valve didn’t shut off and shut done the system. Maybe I had a mainline or lateral line break. My system will know it’s a “unscheduled flow” and shut down the system. Some systems will send you a text or a specific email if this happens. The best part of these, are they are savable, and I have folders with hundreds of pdf. I can tell you what happened on any given day in the past.

Smart systems will reduce water usage using weather data. My system allows me to use local weather data to provide the system with a watering schedule based on many factors. This takes some setup time at the beginning, and the system needs to learn your trends. I currently do not water any of my sports fields with ET or weather data at this point. I do use rain sensors to prevent watering. I use weather data for my landscaped beds, and lawns. Inputting data like soil texture, root depths, plant types, irrigation heads etc., takes time but uses the system to its fullest capability.

We all know about rain sensors. How many of us have them that actually work? Maybe just upgrading to newer rain or freeze sensors is an upgrade. How about a weather station attached to your system? These are not inexpensive, but provide you with hyper local information like wind, rain gauge, and ET. What about moisture sensors? How many should you install per field? Does your field have a microclimate? I have considered using moisture sensors on my lawn areas and ornamental beds. Their cost has come way down.

Installing master valves into your systems are another smart feature. Master valves can be set into two positions, normally open or normally closed. Normally open will not prevent line breaks. I keep my systems normally closed. The mainline and laterals are kept dry. When the system calls for water, the pipes fill. This prevents “unscheduled flows” or line breaks. If you use a lot of quick couplers or snap valves for hand watering like baseball fields, normally closed might not work for you. But with a click of the smart phone, I can manually open the mainline to allow the use of QC.

My systems were retrofitted starting in 2017 and has taken some time to get used to. All our controllers run on cell modems and sometimes connectivity is an issue. This is due to the poor cell phone coverage in town. We installed external antennas to all our controllers for better cellular coverage. Most systems are capable of using WiFi or cell modems. Cell modems are yearly expense but also come with monitoring my systems from the host, a local irrigation contractor who did the smart systems installation. It takes time to see the water savings, but data is your friend and so collect as much data over time as you can.

We have added three more irrigated sites since 2017, all adding to our central control system. Currently we are in construction with a large irrigation project around our high school stadium that will include irrigating lawns, beds and a JV football field. This would make our system then have 15 site controlled remotely.

Most manufacturers have their own versions of smart controllers and the associated equipment. My best advice is to read as much as you can about each product and find a neighboring turf manager that has a system and pick their brain. Find a good contractor you can ask questions and get their feedback.

Ben Polimer is Fields and Grounds Coordinator, City of Weston, MA, and also current President of the New England STMA chapter.