Rhododendron & Azalea News

Plant Tips
Rooting cuttings in winter months	Winter is not too months away...in fact...some areas may experience it shortly. Don Hyatt of the Potomac Chapter gives us some advice...now...on making cuttings from your loved rhodos. May want to share with your friends! Do it now! Winter's ice and snow can often lead to broken branches on your rhododendrons and azaleas. Do not despair...those branches can usually be rooted with relative ease during the winter months...even if they are severely desiccated after lying on the ground for many weeks. Since the branch was a total loss anyway...why not try rooting those cuttings? You do not have much to lose.
simple steps to follow...	To check the viability of cutting material: make a fresh cut at the base of the stem, put the end in water, cover the top with a clear plastic bag to increase humidity. If the leaves plump up in a day or two, the cuttings will usually root, too. You will be amazed at how dead and dried up twigs revive!
more on the cutting procedure...	Make short cuttings...less than two inches long. Wound each side of the stem to expose the cambium and, also remove any flower buds. Dip the end of the cutting in a rooting hormone...such as Rootone or Dip'N Grow...and insert the bottom inch into a container filled with my rooting medium: equal parts peat, sand, and perlite. The medium should be moist...but not wet since excess moisture is the leading cause of cutting failure due to rotting. If possible, briefly move containers outside and spray with an insecticide/fungicide mixture, and allow leaves to dry before bringing them in the house. This reduces potential insect and disease problems. Finally, enclose containers in clear plastic bags to create a mini-greenhouse and place containers under fluorescent lights.
you will see new roots in a month or two...	Cuttings usually break dormancy and begin to grow in a month or two...and by that time they are usually starting to form new roots as well. Do check the containers regularly to remove any leaves that turn brown or cuttings that might rot...but these mini-greenhouses should require no water or other care until ready to transplant in the spring. Another plus...cuttings rooted during the winter months are often large enough by the next fall to make it through their first winter without cold frame protection.

Rhododendrons and plant diseases	Bob George, treasurer for the Cascade Chapter, is more than a collector of funds and payer of accounts...but is an avid lover of rhododendrons and wants to share with others. He realizes some unfriendly visitors to our gardens can cause pain. Let's learn something new. Want to mention virus produced diseases. Whereas humans have several diseases transmitted by arthropods (mosquitoes and other flies, ticks, fleas, bugs, and lice), plants are frequently infected by aphids. Often the virus particles transmitted by these plant lice are shaped in such a manner that they are easily picked up by the aphid...if it is the right species...and transmitted to a healthy plant after getting the particles from an infected one.
aphids are a 'helper virus'...	Although some viruses are not normally transmitted by aphids they may be...if the aphid feeds on a plant infected with what is known as a 'helper virus'. This apparently allows the aphids to pick up the virus particles on their mouth parts. There is still no explanation as to why certain species of aphids seldom transmit viruses.
your garden is not aphid-free...	Do not feel your troubles are over...if you have an aphid-free garden. Certain plants...usually weeds...act as reservoirs of viruses in the garden and soil fungi...as well as nematodes...may also act as the transmitter to the garden plant. Cucumber mosaic really plays for keeps! In addition to being readily transmitted by aphids of many species, it is seed borne in several weeds. One of the commonest is chickweed (Stellaria media). Naturally, the chickweed has evolved an apparently healthy carrier state and shows no sign of infection. There can easily be 11 million seeds per acre in the top six inches of soil...and they may lie dormant up to two years...this is a tremendous reservoir. Other weeds may harbor other viruses and as the total number of weed seeds per acre may be as high as 1-1/2 tons with viability of some up to 70 years (mullein, curly dock), you can easily see the advisability of weeding your garden and staying with it!
no spray kill viruses...	There is no spray which will kill viruses…for they are actually part of the cell and any spray that will kill the virus will zap the plant as well. Research with humans brought forth a meager handful of drugs that can be used as preventives of certain virus infections by probably barring the entrance of the particle into the cell. So far no similar drug is available for plants.
rhododendrons have high immunity...	We are fortunate in growing rhododendrons…for they either have high immunity to viruses...or show few symptoms of infection. The fact that many hybrids...well over a hundred years old...are still easily propagated and are vigorous in both growth and bloom shows this. Few hybrid lilies are kept in good health more than a human life time...for they are susceptible to many deadly or debilitating viruses as well as fungi.

What is pH?	Dear Dr. Rhody: I have read that the medium in my potted plants needs to be adjusted to the proper pH. I have also read that rhododendrons prefer an acid soil. Is this the same thing? What is pH...and how do I obtain a proper pH for my plants. pHuzzled
pH refers to acidity...	Dear pHuzzled: The pH refers to the acidity of a material. Technically, it is a measurement of the hydrogen ion content. The pH scale ranges from 0 to 14...pHs of 0 to 7 are acidic...pHs of 7 to 14 are referred to as being basic or alkaline. A pH of 7 means the material is neutral. I could elaborate further, but the explanation would not be reader friendly.
rhododendrons prefer an acidic medium...	The experts indicate rhododendrons prefer an acidic medium. The preferred pH should be between 5 and 6.5. It is almost impossible for a layperson to determine the pH of the potting medium they use. There are pH meters on the market...but in my experience the ones that cost less than $100 are practically worthless. I have yet to try one that is better than plus or minus 1 pH.
you can do it!...	But...all is not lost. It is actually fairly easy to get your pH in the desired range. Fir or hemlock bark is almost always in an acceptable range and, therefore, an ideal medium to use. It is best if the bark has decayed or mulched for six months prior to use.
importance of pH...	The reason pH is important for plants has to do with the intake of minerals and nutrients. If the pH is too low, yes, soil can be too acidic, the plants have difficulty taking in the nitrogen and phosphorous they need for growth. The foliage will not be the rich green that you expect. Adding lime to the medium or the soil will raise the pH and help this condition. In the Oregon area we rarely have this problem...but it is possible...especially in an area that has been fertilized heavily for years. The fertilizer frequently increases the acidity of the soil...that is...it lowers the pH.
alkaline...too high a pH...	If the planting medium of soil is too alkaline, i.e. the pH is too high, it usually causes iron and/or manganese deficiencies. These deficiencies result in chlorosis...a condition where the veins may remain dark green...but the spaces between the veins will be yellow...the leaves are said to be chlorotic. To remedy this condition sulfur is often applied for a quick fix. Good mulching will also help in the long run. A decomposed mix that would not use up the nitrogen in your fertilizer is best.
your plants will tell you...	In summary, pH is important…but your plants will tell you if you have a problem. Generally, it is always best to use bark in pots and bark or pine needle mulch as an additive for your soil...and you will rarely have a problem. And, as always, plant high for good drainage. Dr. Rhody

Quick guidelines for planting.	A conversation between gardeners resulted in an exchange of some basic information. It is really very elementary and it takes the guessing out of the game. Spring planting: No! Fall is a better time. Roots have time to get established before cold weather...and the soil is easier to work with. Size of planting hole: It is not necessary to dig a bathtub-size hole. Using great quantities of organic materials in the hole: Not so. The material may be too soft and fluffy...and roots will have little reason to leave the area. Stake after planting: Better not!! Swaying in the wind toughens the trunks and causes roots to become stronger. Cutting back stems to balance the roots. No! Do not do! Hormones produced in stem buds, particularly in the tips, helps stimulate root growth and, hence, stem growth. Remove stems at their origin, if necessary.

Propagation of southern native azaleas	Ken Gohring of the Azalea Chapter has a real burden on his heart to alert others to the fun and easy of propagation of these beautiful plants...anywhere. Here is what he has to share. Ken does warn that propagation of native azaleas is more difficult than evergreen azaleas. It is simple and after reading you will want to follow his guidelines. Rooted cuttings. Cutting should be taken from new wood in early May to early June. Suitable wood should snap when broken...although new green shoots are also used. Cuttings should be 3 to 6 inches long, with leaves removed from the lower third or half of the cuttings. Insert cuttings 1 to 1-1/2 inches deep in the rooting medium. Various formulations of rooting medium are used: equal part of perlite and peat, or one part peat to two parts perlite, or a mix of ground pine bark, peat, and perlite but...all include coarse sand in the mix. Cuttings can be placed in flats or individual containers. Humidity is a key element in rooting plants. If one has a large number of cuttings, something like a Nearing frame is useful. The frame should be located in a shady area. If rooting a small number of cuttings, can use a couple of methods: place cuttings in a pot and enclose the pot inside a clear plastic bag, tie the top to retain humidity. make a miniature greenhouse out of a clear, 2-liter soda bottle by cutting the bottom off, place the potted cutting inside, cover it with the top of the bottle. There should be room between the bottle and the edge of the pot to water the cuttings. After obtaining roots, the plants should be fertilized with a liquid fertilizer to encourage new growth...which is critical to survival. Seeds. Propagation by seeds is a good method for species that are difficult to root. Seed capsules should be collected in the fall (that's now in September to early October) before they burst open and spread their seeds. Do not despair if the capsule has broken open...each seed capsule contains hundreds of seeds...there will usually be additional seeds that have not escaped the pod. Store the seeds at room temperature in paper envelopes of open-topped containers. The seeds can be planted immediately...or held until January or February. Best seeding medium is milled sphagnum...but other relatively fine media can be used. Place a top coating of milled sphagnum moss over other media. The medium should be moist...but not soaking wet. Clear plastic containers with an airtight seal are good for holding the sown seeds. Once sealed...they will retain moisture until the plants have sprouted. Remove the air seal once sprouting has occurred. Some propagators use containers with holes in the bottom and provide water through the bottom. Key factor: do not let the seeding medium become dry. Containers. Sterilize by rinsing in a mixture of 10 parts of water to 1 part household bleach. Scatter seeds over the medium...but do not cover...as seeds require light to germinate. Place under fluorescent lights. Desired temperature is around 60 to 75 degree F. Heating cables and other such devices aid in germination. Seeds should germinate in 3 to 4 weeks. Seedlings can be transplanted to individual containers in about 8 to 10 weeks. Other methods for propagation. These include: root cuttings, air layering, traditional layering, stoloniferous sections, heal cuttings, and tissue culture.

Good bugs...good bugs	Good bugs in your garden need shelter, water, corners in which to over winter, and plenty of food, i.e. pollen and nectar. The best fed adults produce the most eggs...which hatch into larvae that consume large quantities of garden pests. The garden should have a wide diversity of plants...lots of herbs and daisy-type flowers. If you have to spray, do not spray everything...just the weevils on just that one rhodo. And, never spray on windy days. Remember tomatoes are very sensitive! Good bugs include: Ladybugs...alas, just read that in England a new giant ladybug, black with red spots, eats other ladybugs...as well as soft fruit...and will give people a nasty bit, enters houses in the fall and when frightened secrete smelly blood which stains curtains and carpets. Watch out for them! They were introduced to North America from Asia to keep down aphids. These are not "good" bugs. The little Hover flies are great aphid eaters. Ground beetles chomp on root maggots, cutworms, slugs, and snails. Look after the good bugs...and you can be sure...they will look after your garden.

Pinching	Jens Birck wrote for his chapter's newsletter about pinching. It definitely is something to think about. The article has been printed in other ARS newsletters as well. In a small garden it is often very beneficial to try to get one's plants as compact as possible. For this pinching technique to work well...it is crucial that the rhodo is in a location that gives the plant the most exposure it will take. Pinching to create the shape we want to achieve in the future should be done at an early stage. When the new cutting or graft is well established, and starts its first flush off new growth...wait until that growth has almost reached its full length. Only then...only then...cut the new growth back leaving a 1.0-1.5 cm stub to dry back. This stub is said to enhance the number of shoots produced if the plant gets maximum sunshine. A new flush will start growing within a few weeks. This new flush will often produced three shoots helping the plant to maintain a dense habit. You can repeat this pinching on successive new shoots for several seasons until you have the structure and shape you want. Old well-established plants about to outgrow the space they occupy could be given the same treatment every other year...thus postponing the inevitable move.

Is the plant dead or alive?	Looking at your rhododendrons and other plants as to whether they are alive or dead as we enter the fall months, here are some points to consider: Best way to be absolutely sure the whole plant...or part of it...is dead is to use your thumbnail and scrape away a small section of bark. If it is brown underneath...the plant is DEAD. If it is green...it is still ALIVE. Then, simply prune back to living tissue. Do not leave dead wood attached in the hope it will sprout...it WILL NOT! The longer you leave it...the greater the chance that disease will take hold. Think ahead to next winter...coming on us soon...and what to do to avoid the same thing happening. Protect the roots of potted plants by insulating the container with bubble wrap. Fleece can protect the tops of tender plants. If water logging was the problem, stand pots on bricks or pot feet. Check the hardiness zone when buying plants.

Root pruning your vireya	Sherla Bertelmann, president of the Hawaii Chapter, shares her speech notes. This is most interesting. Understanding vireya roots is one of the topics I often talk bout when trying to get folks to grasp the important of an airy, well-draining media. Explain vireya have no tap root...but rather very fine surface roots. In the ground, the roots grow close to the top of the soil and spread out vertically from the plant. In a pot, the roots filter throughout the media. Yet, understanding this is not enough! Have taken a pot-bound plant and placed it in the ground...and it still died. Plants grown in containers for a long period of time seem stressed over time, despite applying fertilizer and pruning their tops. What is gong on? Have taken a 4 inch potted vireya, tickled its roots, and repotted it into a larger container with no problem. Why, then, are there problems with taking a larger pot-bound plant and sticking it straight into the ground or keeping one for a long time in the same pot?
back to roots!	We are back to roots! It is not just the media that is important...but the condition and treatment of the roots as well. In the ARS's Noyo Chapter newsletter, April 2003, there is an article on this topic. Dr. Linda Chalker-Scott, Center for Urban Horticulture, writes on how people are afraid to disturb roots believing "the more intact the root system...the better the chances of establishment." While this may be good and well for transplanting seedlings...it seems shrubs, such as vireya, "benefit from a more vigorous approach". Dr. Scott cites several problems of pot-bound plants, such as, "circling root systems that become woodier" and eventually becoming "girdling roots that lead to early death". Pot-bound plants actually lose water especially when planted in artificial media...such as the coconut/perlite that many of us use here in Hawaii. The media is so tightly bound by the roots that it loses the ability to hold and absorb water resulting in the plant stressing.
signs of stressing...	Some signs of stressing are: new growth that continuously wilt, leaves dropping, or root rot occurring almost over night. If a vireya is transplanted into the ground "with the plant as art of the root ball" the root development is inhibited and will not grow into the surrounding soil. This explanation helps to understand why my root-bound vireya died when I transplanted it. It helps to understand why my pot-bound vireya has stress. What is the answer? root pruning! It seems pruning the crowns of your vireya will produce new growth...it stimulates healthy roots. Before transplanting, it is recommended “to remove as much of the container medias as possible,” bare-rooting your plant. Herb Spady of the Willamette Chapter believes this is best done early in the year to give plants time to grow new roots and become established before the hot summer heat. "Some of the harshest techniques result in the healthiest plants!" Proof of this can be seen in our vireya growing on the hillside at the Zoo. Last year we received very root-bound plants to add to our plantings. Instinctively, with fingers crossed, I took a shovel and sliced off almost half of the root balls. Today all vireya treated this way are growing fine. None were lost.
get bold...real bold...and chop, chop...	Over time am becoming bolder in the treatment of my own vireya...pruning...all the way down to hard wood...then slicing off large portions of their roots...when transplanting. All with good results. It is through trial and error, sharing experiences, and great articles with good advice...that am learning more about gardening and vireya. Viva Gardening! Viva Vireya!

Haiku	The Portland Chapter is so fortunate to have Peter Kendall as a member who is gifted in so many ways. He wrote the paragraph below for an October newsletter...and to end this Plants Tips section. It is very important to include it now... Yet October In the rapidly falling leaves the winter to come. The depth of autumn its colors, and that of the jay this overcast day. In an evening light trees, in drawn out autumn color a hawk in profile. Thanks to you, Peter, for the inspiring items you bring to your members...and

A daily reminder...	Good words and good deeds keep life's garden free of weeds!