Be conscious of summer temperature when watering cuttings set to root. All plants can be vulnerable to that first blast of hot water from a hose or watering can, but new cuttings are especially at risk. They exist in porous rooting media, usually in small spaces with few or no roots. The hot water sitting in just a few feet of garden hose can even burn their little green stems. Whether you are using Hormex Liquid Concentrate at the time or not, use the baby bottle test on the water that will irrigate the rooting bench – if a drop feels hot or cold to the inside of your wrist, wait a bit.
June, 2012
Cloning Tomatoes
Even those who live where gardening is a twelve month activity sometimes have trouble finding just the plant they want when they want it. If we can find one we like, we clone it to keep it. At other times unfortunate things happen and our desire is to salvage the situation drives us to propagate. Sometimes it’s just pure fun to see if we can do it! In the last 2 weeks, different individuals have asked me how to deal with all of these contingencies and the answer is the same – clone that tomato!
Lots of people in warm climates grow fall tomatoes, planting them in late July for harvest through November. More people would grow them if plants were available but often they are not. You can start seeds for heat resistant varieties or clone your own from the spring plants if they are not pest-ridden. Tomato plants often outgrow their cages or poles. Right now I am looking at a cherry tomato supported by 3 huge bamboo poles that is busting out all over, its branches heavy with fruit. If a storm hits like last week, it will break as one did that is now a bowl of green tomato pickles and two cuttings in water on the windowsill. 3 people have related the same experience (it was a big storm) and asked if they can root the breakage to start more plants. Fortunately, they can clone.
You have a choice of rooting media for tomatoes. Unlike most plants, healthy tomatoes are ready to root and will develop decently thick roots in either water or a lightweight rooting medium. The type of cutting is more critical since those taken from the tip of a branch are much more durable. Some people will root suckers, shoots that form where a lower leaf springs from a main stem, but I much prefer the results from tip cuttings. Take a 6-8 inch cutting from a healthy, insect-free, bright green tip and strip the leaves off of its lower half. Slip the cutting into a bottle of water, preferably a tall, narrow one shaped like a beer bottle so the leaves are supported by its rim out of touch with the water itself. The stem will root at the bottom first but also along the stem itself in most cases. I dip the end of the cutting into Hormex Liquid Concentrate and put 3 drops into the water, too. To start new tomato plants in lightweight, soilless mix such as Metro Mix, use a deep or wide pot. Like when you use water, the idea is to get most of the tomato stem into the pot because it can develop roots all along its length. That results in a much sturdier plant, one that is better able to grow in the heat of summer because it has more roots to take up water and fertilizer. Such cuttings can be more difficult to uproot in a thunderstorm, too. It’s a win-win for the propagator and simple to set up.
Where to put those future tomato plants during the cloning process depends in large part on the medium and the conditions where you live and garden. A temperature around 65-70 degrees works well for both and can usually be found outdoors in the shade or inside on your windowsill. I live where it is much hotter than that outside, so I use the windowsill for water rooting and put the tall pots under a plant light in the spare room. We call it the spare room even though my husband’s lifelong friend and his dogs live there most of the time. Why we do that, I cannot say for sure, but it is probably because to do so suits him.
Extra humidity in the area is not usually necessary for cuttings in a bottle of water, but if it is needed for those in a pot of soil, a simple plastic cloche will suffice or you can make a simple rooter out of a 2 liter bottle. Cut off the top 2/3 of the plastic, poke holes in the bottom of the base, and fill it with the media. Dip the base of the cutting into HLC and slip it into the pot, then use the top to cover the base by sinking it into the mix. Leave the top off to allow fresh air in and remove it completely when you water or if condensation forms inside the top. Once you get either method set up, it is just a matter of adding water to bottle as it evaporates and watering the soil in the pot often enough to keep it just damp. Add HLC once a week for fastest rooting – a drop or 2 in the water will do just fine. Within 10 days to 2 weeks there will be about an inch of roots; in 3 weeks either kind of cutting should be ready to pot up or plant out.
Use The Right Thing
Strength matters, whether it is the alcohol content of your favorite brewski or the rooting hormone you choose for a particular plant. While it may be considered more efficient to down the more potent beer, using a stronger rooting hormone than a plant requires will not be rewarded with greater result. A plant that can root in Hormex #3 will find that growth stunted in Hormex #45 and vice versa. Use the right strength for the right cloning power to produce roots in the fastest time. With 50 years of experience to document success, Hormex Rooting Powders are formulated at 6 different strengths for particular plant species from perennial Mints to Yew trees and conditions, such as dormant hardwood cuttings. Make smart choices, in beer and rooting hormone strengths.
Hormex and Cloning Power
The caller sounded puzzled. He’s been rooting cuttings for years, heard me talk about Hormex on the radio, and visited the website. In all those years, he said he’d never seen more than a couple of different strength rooting hormone products. Does it really make a difference which strength you use? Why not just get the strongest one and use it for everything? His questions gave focus to this week’s blog.
Hormex Rooting Powder comes in 6 strengths with specific applications to suit several plants and plant groups. They are numbered and higher numbers indicate greater strength concentrations of IBA, the active ingredient. IBA, indole-3-butyric acid, is a naturally-occurring plant hormone vital to the cell elongation process involved in rooting. Just as different plant groups thrive in a range of sun, soil, and maintenance conditions, they develop roots best at particular levels of the rooting hormone IBA. To stretch the analogy a bit further, a plant that needs only weekly watering can be drowned by greater amounts that fatally reduce the available oxygen in the root zone. In the same way, a plant that can root in Hormex #3 will find that growth stunted in Hormex #45 and vice versa. Use the right strength for the right cloning power to produce roots in the fastest time.
I’ve been thinking about this issue a lot since that call last weekend and the short answer is: Yes, it makes a difference which Hormex product you use and No, it won’t work to use the strongest for everything. Now that we’ve cleared that up, here are some notes about the plant groups and their preferred Hormex Rooting Powder.
The label of HRP #1 explains that it is for use on easy to propagate plants including common shrubs and greenhouse plants. Herbaceous or green plants like members of the square-stemmed Mint family (coleus, verbena, etc.), some plants which are woody but root easily with their leaves on such as jasmine and rose, and a roster of in-between plants respond well to HRP#1. This strength works for stems that are green at times and woody at times such as bougainvillea, raspberry, azalea, and willow. It is the go-to strength to try first and also works on plants as diverse as begonia and African violet.
As their strengths increase, Hormex powders stimulate rooting in woodier plants and harder-to-root evergreens. For example, HRP #3 works for popular evergreens like junipers, fruits such as blueberry, as well as pyracantha and Daphne. All need coaxing to form roots but will be discouraged by stronger Hormex formulas.
The truly difficult to root evergreens and dormant hardwood cuttings of deciduous azaleas, grapevines, lilac and maples including Japanese maples respond well to the stronger HRP #8. These plant groups need higher levels of IBA to speed rooting and improve the quality of roots formed. I know this is just one person’s experience, but I had tried and failed to root native azaleas several times before I used #8. The cuttings I took in February are looking good!
By now you have probably realized that some members of a particular family are more difficult to clone than others. Junipers, for example, can be easy or difficult depending on the species or cultivar. Chinese junipers take #3, but the truly tough customers are the Hollywood junipers which need #16. Common names can be misleading, too, like this example: classic arborvitae will root with #3, but the pyramid arborvitae (actually Thuja) responds to #16. This Hormex product as well as #30 and #45 are intended for use with very difficult to propagate and very particular species. Their rooting will be slowed or not helped at all by lesser formulas, just as the plants that can root with less concentration will be overwhelmed by greater strengths.
One more note: I was first introduced to Hormex Rooting Powder in horticulture school, but found a stalwart fan when I began working in California. A grower friend of mine gave me a variety of cuttings when I toured his greenhouses. As I was leaving he summoned me to the head house, the greenhouse equivalent of a potting shed, where a jar of Hormex sat on the bench. He poured about a tablespoonful into a clean envelope and handed it to me with instructions to use it on the woody cuttings. Since I knew him to be a man of few words, it was surprising when he launched into a 5 minute tribute to the great cloning successes he’d had since starting to use Hormex. But once I started using it, I understood completely.
Nellie Neal is a passionate propagator and owner of GardenMama, Inc. She advocates for gardening 24/7 at her website, www.gardenmama.com. Ask questions and comment about this blog on the Contact Us page of www.hormex.com.
Avoid Overwatering
For more success in propagating flats of coleus, shrub cuttings, and anything else you are rooting outdoors in the shade, monitor rainfall and irrigation closely. Just as overwatering kills more container plants than any pest, saturated soil can spell doom for vulnerable cuttings. Roots and root hairs can be easily overwhelmed when too much water in the soil deprives them of the oxygen they must have to grow. Set up a simple bench that will elevate the propagation area above ground level and allow the containers to drain. I use 2 cement blocks with 3 2×4’s laid across them, but then my style does run towards the utilitarian. However you do it, do it and keep a plastic drape handy, too. You can control the rooting medium and your watering habits, but may need to stave off a summer rainstorm to keep from overwatering cuttings.
Blueberry Wisdom
If you have a wonderful old blueberry bush and want more of its superb fruit, why not propagate it? As long as it has no patent to protect it from your efforts, go ahead now and check the wood. New growth is soft, later it is called semi-hard, but the wood you want is between the two and usually happens about a month after the leaves are fully expanded. Read the entire blog for details, but use this tip when taking soft, semi-hard, or in-between cuttings of any plant: get them in the morning while they are fully hydrated to prevent wilting before the new roots appear.
Semi-hard Timing
The neighbors probably think I’m dotty, and it’s not the first time. A recent surge in temperatures has quickly hardened the tender green shoots of several shrubs I want to root this year. So for several days I’ve been making a regular tour of the front garden, bending stems to see what’s ready to root and I’m sure it looks as silly as my early morning efforts to relocate ladybugs from the Scotch roses where they breed to my vegetable plants!
June is traditionally the month when new growth begins to firm up on woody plants in the subtropics where I live. The transit to semi-hard wood, what I call summer wood, happens earlier in tropical areas and perhaps as late as July in the temperate zone. Finding stems that feel right can be like testing a pound cake for doneness. Every recipe gives you a time and temperature for baking, but you are always advised to adjust for your own oven and even the conditions where you live, such as elevation and humidity. That means you have to test with a toothpick to be certain when the cake is just done to avoid under or overbaking. Likewise in the garden, you know that the wood that roots best is neither tender green nor completely hardened off to woody. The new growth will collapse and rot before it roots and harder wood hasn’t the capacity to root during the growing season. Later in the year, of course, many hard wood cuttings can be rooted using the bundle process. But to find semi-hard wood, its ‘doneness’, you have to test, so that’s what I’ve been doing and maybe you are, too. Let me know if you are rooting woodies – and whether they have made it to semi-hard wood where you live.
Like lots of gardeners, I have a lorapetalum that cannot be contained. Years ago, the label said it would be easily maintained at 4’ tall and wide. Hah! Not wanting to prune it 6 times a year, I soon turned it into a small tree and it is beautiful. Meanwhile, across the yard my neighbor has ignored an old stand of azaleas under pine trees. Privet and other weed plants had taken over and years of pine straw covered everything, creating an eyesore at least, a traffic hazard and a pest haven at worst. A dear friend got tired of not being able to see to get out of the driveway and cut most of the mess down. Now I want to root some Lorries for my side of that space to distract from whatever grows back. The stems are stiffening quickly and should be ready to cut in two days.
It’s a good day when I can add a vase of cut flowers to the dinner table. Every vase should have roses, but I grow mostly shrub types that do not cut well. There is one, though, that has it all for me – easy to grow, stiff stems, and big fragrant flowers. It is a classic tea rose called Aloha given to me as a cutting that I have propagated into 4 reliable sources for the table, but I want more to plant and give away. That rose has been in bloom since February and I deadheaded it about a month ago. The new shoots are still a bit green so I’ll have to wait – and keep testing.
Lately I have really gotten into lower growing shrub roses and have created 2 hedges that surround a large bed. Now I want to fill in one more section with a found rose from Texas known as Caldwell Pink. It’s usually 3 feet tall at most, but I have one that starts blooming much shorter than that and will make a fine hedge. In previous years, I have rooted non-flowering stems of CP because the flowers never stop on the new growth even if I do not deadhead them. That’s the wood I’m waiting to collect now but it still can wrap around my finger too easily. Maybe in a week.
One of the finest native plants I know is beautyberry, Callicarpa americana. In high shade, it is a splendid fountain of green leaves with metallic purple berries bursting from every leaf joint. But it is too huge for the front garden so I was tickled to discover a dwarf form at a nursery in Texas. In the interest of space (and because I just had to have that yellow cestrum) I violated my personal rule: when buying new plants out of town, always buy 3 so you can plant two and grow one in a container for insurance. The one has done well, but it is old and the shade is getting dense above it. The plant has given me one more reason to propagate, to continue an old plant with a new clone. It is ready to cut now and this time, I’ll root at least 3 including one to grow in a big container opposite the yesterday, today, and tomorrow plant (Brunfelsia) in my courtyard. Come to think of it, the ytt is getting old, too – I’d better check it.
All these cuttings will root fine when I make a fresh cut to roll in Hormex Rooting Powder right before I slip them into my usual lightweight mix. I root outdoors in shade during the summer, but the success numbers might be better if I used a mist system. Hmmm, I could string some misters over the outside area and if the next month is very dry, it could make all the difference. I’ll let you know how that goes!
Propagating Woody Fruits
I’m picking 2 pints every other day from my 3 old blueberry bushes and another pint from a couple of their offspring rooted in 2010 and planted last year. Blueberries and other woody plants put on lots of new growth most years and so can have hard, soft, and semi-hard wood on the plant at the same time. That makes it both harder and easier to decide when to take cuttings, and indeed, there are 2 times worth considering. One opportunity, hardwood cuttings, has passed for this year, but the other, soft-er wood cuttings, is ready for your mist chamber. Yes, a mist chamber, which is easier to do than you may think and valuable for rooting lots of reluctant cuttings.
What I call soft-er wood is not the newest growth, but neither is it classically semi-hard. Once the new growth comes on and the leaves are fully expanded, it will be about a month before it is firm enough to use. Because they are still relatively tender, blueberry cuttings can wilt and so need mist while rooting. Blueberry and similar cuttings need to retain their leaves in the process, but the cut stems cannot take up enough water to hydrate them and root at the same time. A few seconds of mist at regular intervals allows leaves to retain the water they would otherwise lose to transpiration. Those who have greenhouses can devote a part of a bench or use the space under a bench to create a rooting box with an intermittent mist system. Timed mist provides a burst of fine droplets to raise humidity levels and introduce moisture to the cuttings, most often inside a plastic drape. If you use smaller propagation hoop houses, it is usually necessary to provide mist to the entire structure to control temperature. Self-contained, commercial mist systems can be pricey, but their elements are not. With a basic understanding of how they work, you can customize a system for your space. Check out this good how-to article that will guide you to build a propagation mist system: http://www.ehow.com/how_5721112_build-plant-propagation-mist-system.html.
I want to be clear – soft-er wood blueberry cuttings can be a bit tricky to get going and the usual success rate is about 80% for experienced propagators. If you want 10 plants, stick 15-20 cuttings for insurance. True soft wood cuttings will be damaged as you stick them into the rooting media and crushed tissue collapses quickly. True semi-hard wood is stiff in comparison. You are seeking the in-between wood and like so many things, once you see it, you know it. Take 6” cuttings from the tips of blueberry stems and remove the leaves from the lower half. Leaves inserted into rooting media will rot and can keep conditions wet and worse, introduce fungus. Use the medium of your choice – I like a soilless mix with a bit of perlite added for woody plants. Don’t scrimp on the pot size for woody cuttings. Since at least 3 inches of stem will be in the soil, provide 3 more inches below so water does not saturate the mix and soak the cutting. In a practical sense, this means you can use a deep quart sized pot for each cutting or a regular one gallon shrub container for 3 or 4. Roll the tip of the cutting (you did cut it on a slant, didn’t you, to increase surface area?) in Hormex #8 and stick it into damp mix. Put the pots under mist and water as needed to keep the mix moist but never super wet. When you do irrigate, add 1 t of Hormex Liquid Concentrate to each quart of water.
If you are interested in hydroponic blueberry propagation, explore this article about
a mist system for propagating blueberry plants: http://www.ehow.com/how_12134664_make-mist-system-propagating-blueberry-plants.html. Some growers prefer to use this method because it reduces the chances of encountering fungal infection in the soil used for rooting and because it is very efficient. I have not built this one, but it works like the commercial types and would be intriguing to try out.
Just one more note, about plants that are patented. These plants are usually new to the market, after years of trials done to be sure they are better than existing choices. To protect the expensive research done to develop the variety, a patent is issued and propagators shell out big bucks for licensing rights plus a fee per plant for the right to grow them. Non-licensees (like you and me) are not allowed to propagate patented plants for profit and sometimes not even for personal use. Check your varieties and be sure they are not restricted before you root them. While prosecution may seem unlikely, there is an ethical issue here. Simply put, it’s stealing and you shouldn’t do it.

