Growing Magnolias Successfully – Growing Magnolias from seed
There has to be one fascinating and beautiful tree or shrub that I like above all others… the Magnolia.
Elegant and Oriental, delicate and aromatic, colourful and beautiful!
Personally I don’t think that many plants, shrubs and trees come anywhere near Magnolias at that time of the year!
When they start to blossom, my wife and I await the show of beauty and fragrance with anticipation.
Just before, during, or on our wedding anniversary in April, they are in their glory, and it is a romantic and nostalgic time, as we have always marked it as the ”Magnolia month” which is our marriage month. Filled with anticipation of the remaining year, and also it is the start of some of the most wonderful fragrant and beautiful blooms in the garden.
When nothing in the garden is really happening, the magnolias begin to swell their hairy or furry buds, and they split open. The next thing the flower protector husks fall to the ground, leaving the beautiful flowers to open and unfold to realise their glory. Hopefully if there are not too many severe frosts, the flowers will stay white and beautiful, maybe tinged with pink at the base as in the “Magnolia Soulangiana”; or “Heaven Scent” shown here.
The flowers on most Magnolias open from late March to early April, except for M. Grandiflora, which in the UK (52 degrees North) flowers from July to October if the weather is good. In the UK that is a big “if” as a bad summer can check them and stop them flowering much at all! (this happened to me one year, so all I had were two feeble flowers on it)
We will refer to Magnolias as “M. Soulangiana” for example; for a short version of the name abbreviated “M.”.
The species Magnoliaceae as they are called, are varied and beautiful, in many colours, shapes and sizes.
The most beautiful that I like is the only evergreen magnolia, the M. Grandiflora, having evergreen leaves, and large waxy 6″ to 8″(UK Inches, 1 inch – 25.4 MM, or 2.54 CM) flowers. The scent is heavenly and heady, making your head spin, and having a distinct citrus lemony smell nice enough to eat.
They grow in an acid soil, against a South facing wall or in a sheltered South facing garden. One prime example is M. Grandiflora “Exmouth”, having an emphasis on growing in the South of England where it may be warmer. The picture below is my own M. Grandiflora in 2009.
One thing that amazes me about Magnolias, and a “must see video”, is when David Attenborough in his “Private Life of Plants”; “Travelling” shows a 2000 year old Magnolia seed in amongst some other dead seeds in a proven 2000 year old burial site. (Courtesy of the BBC for this brief clip)
The seed is planted, and grows into a Magnolia plant, that flowered after 10 years. However when it flowered the experts noticed that it has a different number of petals than we find on this variety today, and is a variation of this variety that we don’t have now… amazing!
It appears to be a M. Kobus, and is very elegant and beautiful with the flowers fully open way before any leaves are on the plant which really enhances it’s beauty.
Now wasn’t that just special?
So on to the history of Magnolias briefly…
Magnolia genus is one of the oldest among other plants genera, and may be called an ancient genus. Fossilized Magnolia flowers along with the bugs (main pollinators of this plant), were discovered in rocks dating around 100 million years old. Magnolias are considered to be indigenous to two main areas: the Himalayas foot of North China and the Gulf Coast of Mexico and Central America. These are the places magnolias started their victorious parade of inhabiting countries and continents. In the wild magnolias grow in dense woodlands, in forests with moist, humus-rich soils. Mainly, magnolias grow in tropical and subtropical climates (USDA zones 9-11); they are also widely spread at the Mediterranean coast of Europe, the Caucuses Coast of the Black Sea and along the Coastal Asia Minor. Many magnolia varieties are relatively hardy, some up to zone 7 or even 6. The hardy kinds grow wild in the Himalayas, Japan, China and North America. Magnolia acuminata, the Cucumber Tree, is a native of North America.
The plant was originally named by Charles Plumier, outstanding French naturalist, mathematician and artist. The name was given in honor of Pierre Magnol (1638-1715), French professor of botany and director of the Botanical Garden of Montpelier. He was one of the innovators of the current botanical scheme of classification and was the first to introduce a Plant Family to botanical taxonomy. His work inspired the Father of the Plant Classification System (Linnaean classification), the eighteenth-century botanist Carl von Linne (Linnaeus).
Magnolias are represented by over 240 species and hundreds of varieties and are highly diverse in forms – from tall trees up to 60-100 ft to various size shrubs. There are about as many deciduous species as there are evergreen species.
The best methods of Magnolia propagation are by seeds, air layers and grafting (desired variety grafted onto a seedling rootstock). Cuttings are usually difficult to root except for a few species.
Magnolia seeds are usually slow to germinate. Propagation may be encouraged by using special hormone soaking (such as natural growth stimulants Epin and Cirkon) and providing a bottom heat. Warm temperatures above 85F induce germination. Seeds should be sown when they are as fresh as possible. Use only light, well-drained mix which should contain such components as peat moss, Pearlie, sand, coconut fiber, pine bark. Proportions may be experimented. The seeds may take as long as 18 months to germinate (especially if not fresh or under unfavorable conditions), so give them a good chance before discarding. Remember that seedlings are not necessarily true varieties since the natural hybridization may occur.
When you have collected your long ripe magnolia seed pods and their bright orange seeds, remove the seeds from the pods and store them in a mouse proof container. Do not put them in full sun or somewhere hot such as a radiator but do not put them somewhere damp where they will rot either. A sealed plastic box is fine and do not be worried if the seeds grow a little mould.
In early March prepare a box or tray of say 18” x 12” x 3” (deep) with a mixture of soil, peat/compost and a little sand. The tray or box must have good drainage. Take each seed and rub it between finger and thumb, or wash in washing up liquid, to remove the sticky orange skin around the seed which in the autumn was designed to make a bird or rodent see and eat it. All you are doing is what the animal’s stomach would have done to remove the seed covering. By March it will probably look more brown than orange but it still needs removing. If you do not do this your germination rates will reduce by 50-70%.
A box of the size outlined above will take about 40-50 individual seeds placed about an inch below the surface.
Then cover the box or tray with a piece of glass to make it mouse and slug proof. This is essential!
After 6 or so weeks you will see germination taking place but this will occur sporadically (hopefully) over several weeks and not all the magnolia seedlings will appear at once. The temptation to remove the glass is huge but be careful. Build a bit of a frame over the seedlings and keep the glass over the top. Again this will keep mice out but small slugs and snails can still be a problem.
In hot weather in May or June put newspaper over the glass to shelter the young seedlings from scorching in direct sun. Once they produce their secondary and tertiary leaves this will not be necessary.
If you have done everything right you will, by September, have a tray of seedlings which are variously between 4 and 12 inches tall.
Leave well alone while they are in leaf. However, when they shed their leaves and go dormant you can dismember the box or tray and separate the roots of the individual plants. Pot them on into 1 litre pots before they come into leaf and then again into 3 litre pots in the autumn.
You then have a plant – perhaps even a unique hybrid of your very own – which should be big enough to plant out in the garden the next spring. Alternatively, if you are a magnolia breeder, you will have a perfect rootstock for grafting in the following year.
Some hybrids are sterile and can be reproduced only by clones (grafting, cuttings, air-layering).
Some deciduous species, likeMagnolia stellata, especially those of slender growth, can be propagated in summer by 3-4″ green cuttings taken after the flower buds have formed. The shoots should have a small heel of the older wood still attached and be inserted in a bed of sand/pearlite in a mist-house. As soon as they’ve formed roots (may take months), they should be potted individually in containers with well-drained potting mix. At this point, liquid fertilizer will be essential to encourage vegetative growth. The following spring the young plants can be planted out. Some magnolias bloom very early in the spring before the leaves, some bloom later in the spring and still others during the summer and early fall. Asian magnolias have the most valuable flowers which become even more beautiful as the plant gets older.
Rare species and hybrids should be propagated by grafting in spring when the plant gains the most of its vigor. Grafting on a hardy seedling species has several benefits. First of all, the seedling downward root system provides the best plant establishment unlike shallow roots of a cutting or air-layer. The plant will better withstand strong winds. Besides, a hardy species used as a root stock will ensure better hardiness of the whole plant. This is the reason why, for instance, Magnolia x Alba is often grafted on Magnolia champaca seedling which is hardier, besides, Magnolia x Albahybrid is basically sterile and can not be propagated by seeds. Magnolia acuminata and Magnolia tripetala are also popular root stocks.
In the process of air layering, the bark is removed by cutting away about a 1″ wide ring from around the circumference of the shoot. Wet sphagnum moss (or another moisture retentive medium) is bunched around and covered with plastic and sealed with aluminum foil and must be kept damp at all times. Roots will form around that ring. It may take months.
Another method is to layer the lower branches into container with a potting mix, placed under the tree or bush. The branches should be slit and pegged down in the spring, and shouldn’t be disturbed for two years.
Do not let them flower until they are a well established plant with a good root-ball if they are in pots. The flowers if they are encouraged too early can drain the plant, possibly kill it, or stunt its growth. With some patience it is possible to get Magnolias to be a joy to your garden.
Recommendations to grow them on well in the garden is to keep the soil ericaceous (acidic) by using plenty of peat, leaf mould, and “Miracid” (Miracle grow soil acidifying plant feed) or its equivalent. Dig a large trench around the site where the plant is going to be placed, and condition the soil well. feed regularly each month during the growing season with “Miracid”, and chelated iron, to avoid yellowing of the leaves and general bad health of your plants.
Do not allow them to dry out, and only feed them as the instructions recommend to avoid damage to the roots and ultimately your plants.
Some of the biggest killers or what can stunt the of growth of your Magnolias can be…
- Moving plants in the spring/summer, and damaging the roots, or letting them dry out. Only ever move small plants when dormant in the winter before the frosts, and ensure you have the entire root system. Large trees or plants will be best left alone. I have moved small plants, but be careful.
- Lack of moisture, keep the soil moist around the root after planting and during drought periods, especially while they get established.
- Boggy and very heavy clay waterlogged soil; ensure your young plants get enough drainage. Mulch the soil well with leaf mould and peat, and even make a gravel pit soak-away drain nearby if the problem is severe to reduce the chance of flooding. This can be achieved by digging through the clay, and filling the pit with loose gravel and sand, but not close enough to be affecting the roots of the tree.
- Alkaline or Chalky soil; condition your soil. Add leaf mould, peat, and soil acidifier into the planting area, and mulch regularly. Avoid damaging the fleshy roots that are often found close to the surface. Do not over feed as below to avoid root damage.
- Lack of Iron in the soil. Use chelated iron pellets to avoid yellowing of the leaves. Do not overfeed them, and do not burn the roots with excessive feed concentrates etc.
- Plant tender varieties against a South facing wall or in a sunny well sheltered area of your garden. Avoid harsh winds and severe frosts, as they may damage the plant and the flowers will burn and turn brown quickly on the edges, which also looks unsightly.
- Avoid excessive pruning; just shape the plants to suit your requirements gradually. Remove crossing or rubbing branches early before the are too woody and heavy, and before they affect the overall tree shape.
- Do not prune when the sap is rising in the spring; wait until the leaves fall and the sap is reduced. Always seal cuts with pruning sealer to minimise the risk of pests and disease, as well as excessive sap loss.
I have noticed the beginnings of “scale insects” on my magnolias, so the following artice quoted below would be useful to follow, and I will be implimenting it too…
“Magnolia Scale And Its Control, HYG-2003-94
Magnolia Scale And Its Control
David J. Shetlar
The magnolia scale, Neolecanium cornuparvum (Thro), is one of the largest and most conspicuous scale insects known to occur in Ohio (and no doubt elsewhere as well!). Adult females may reach nearly 1/2-inch in diameter when fully grown. The scale is shiny tan-brown and smooth. As the scales grow, they are often covered with a white mealy wax. This wax is lost at the time that the crawlers emerge.
As the name implies, this insect is primarily a pest of various species of magnolia. Saucer, star, lily and cucumber tree magnolias are the most common trees attacked. It has also been reported to feed on Daphne and Virginia creeper.
Magnolia scales have sucking mouthparts and when heavy infestations completely encrust branches, the branches often die. Badly infested branches and twigs are weakened and growth is retarded. Leaves may also be under-developed. Under a continuous and heavy attack trees may be killed. Like most soft scales, the excess plant sap is excreted as a sweet, sticky material called honeydew. The honeydew drips onto the foliage and branches. A dark fungus, called black sooty mold grows on the honeydew which results in the leaves becoming blackened. This greatly detracts from the plant’s normal ornamental value. The honeydew also attracts a ants, bees, wasps and flies which feed on it.
Description and Life Cycle
The magnolia scale spends the winter on one to two year old twigs as tiny, dark-colored nymphs. As temperatures warm in the spring, the scales begin to suck sap and have molted once by early May. At this time two distinct forms can be found, males and females. The males remain small, about 1/8-inch, and soon turn a translucent white. Soon after the males turn white, they emerge as tiny, pink to yellow gnat- like insects with two long waxy threads extending from the tip of the abdomen. The females continue to expand and by early June, they have turned a brownish-purple color. This is also the time that they produce excessive amounts of honeydew. By July the females are covered with a powdery, white waxy coating and are turning more of a yellow- tan color. By late July and August the adult females begin to give birth to their young known as crawlers. The tiny, mobile crawlers move around until they find a suitable feeding site on which they settle down, feed, and remain through the winter.
Though there are several predators and parasites known that attack this scale, they rarely do an effective job of control, especially on smaller magnolias.
- Obtain Pest Free Plants – Most of the magnolia scale infestations come with the plants, so carefully inspect the branches of plants being considered for purchase. The large scale exoskeletons often remain from the previous season. Any plants with these remains should be avoided.
- Summer and Dormant Oils – Horticultural oils (often called summer oils) at 1.5-2.0% applied after the crawlers have settled in late August can be very effective in reducing the scale population. Be sure to thoroughly wet down the stems and leaves. Dormant oils can be applied in October to November and again in March to kill the overwintering nymphs located on the stems. Be sure to check the spring buds as some damage may be caused on the flower buds if they have begun to swell.
- Standard Chemical Control – Magnolia scale can be satisfactorily controlled with a variety of insecticides if applied when the insects are in the freshly settled crawler stage. This is usually in late August to early September. Sprays applied before the crawlers are present, or after they have become dormant in the overwintering stage will have little effect. See Bulletin 504 for currently registered insecticides.
NOTE: Disclaimer – This publication may contain pesticide recommendations that are subject to change at any time. These recommendations are provided only as a guide. It is always the pesticide applicator’s responsibility, by law, to read and follow all current label directions for the specific pesticide being used. Due to constantly changing labels and product registrations, some of the recommendations given in this writing may no longer be legal by the time you read them. If any information in these recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned, nor is criticism meant for products not mentioned. The author and Ohio State University Extension assume no liability resulting from the use of these recommendations.”
Be aware of these horrible pest scale insects; I have had to spray my small M. Liliflora Susan, and my Skimmia Japonica hedge because of these horrible virulent insects deposited from the Maple trees in my street.
They will suck the life out of your plants, shrubs and young trees, killing tender branches, deforming and stunting their proper growth.
One suggestion to try is to spray them with s strong detergent or washing-up-liquid spray; but to only do this on branches and trunks of shrubs and trees, but to avoid the foliage.
I did have a measure of success with this method, without pesticides, and without damage and leaf drop to my plants.
I did a bit of “detective work”; and I have found the source of these horrible scale insects!
Where do you think!…
Well I can’t really do a lot about it..
It is the beautiful “red leaf Maple” trees lining our street! DOH!
Cross-contamination is definitely a risk; but if it is street trees you can’t really do a lot about it, other than take remedial measures as and when you can!
I certainly hope that you have success growing your beautiful Magnolia trees, and enjoy many years of flowering, hopefully without being dogged by nuisance and pest insects and infections!
Remember, a healthy Magnolia will certainly flower in the spring, and often in the Autumn a little as well, and sometimes the odd flower all though the summer. The Autumn flowering isn’t as spectacular, and the flowers are hidden more by the leaves still on the tree.