Welcome to the seed propagation area - here you will find basic information on the subject of raising plants from seed. Raising plants from seed is fun and when you bring bulbs into the equation very cost effective (if you can wait!) All the information here is based on my own practices which have evolved over the years after carefully learning from my 'mistakes'. If you have success raising alpines from seed, please don't change a thing but if you do have problems, there may be information here of use? I have divided the beginners section into two for now, this section will be expanded in time.
Also added now is a section on the use of Gibberellic acid, primarily with reference to the germination of rosulate Violas and notes on dealing with sort lived (ephemeral) seed.

ALPINES FROM SEED - NOTES FOR BEGINNERS

CHOOSING YOUR COMPOST

Careful choice of the compost to sow your seeds in may make all the difference between success and failure!
Two essential requirements for seed to germinate are water and oxygen (other factors will be dealt with later). The medium should therefore be open in texture yet water retentive. In practice this is impossible to buy 'off the shelf' so a little mixing of your own is required. I have found a mix of equal parts John Innes compost, 5mm grit and fine vermiculite to be ideal. The John Innes I can obtain locally is loam based and I use either No 2 or a lime free variant (when diluted down, the nutrient level is not excessive). If you already have good success - carry on! If you don’t, give this a try.

WHEN TO SOW?

This is usually learnt by experience, trial and error. For the vast majority of alpines, the choice of sowing times is fairly simple, either winter (Dec-Jan) or spring (Mar-Apr). It pays to choose correctly as the wrong choice may seriously delay germination or even prevent it! If in doubt for a given species, the ideal strategy is to sow some winter, the rest in spring and keep a record of the results! Reference books may help and Norm Deno's 'Seed Germination Theory and Practice' is an invaluable guide to shortening the learning curve of decision making. Some specialist alpine seed catalogues now give germination requirements, a very useful development.
Whilst it is difficult to generalise and there will be exceptions, the following genera are best sown during:

The seed of some genera either do not store well (see Ephemeral seed below) and soon lose viability or develops inhibitors which may delay germination for long periods. Immediate sowing is advocated for the following genera: Of course, seed may be sown at any time using artificial means eg refrigerator or propagator to control temperature. Seed placed in a small amount of moist vermiculite sealed in a polythene bag may be refrigerated for 4-12 weeks to simulate a winter even in mid summer! The same method may be used to treat seed to warm temperatures during the winter months, useful for some genera as Alstroemeria which may then germinate treated subsequently with cold.

HOW TO SOW

Have a supply of clean pots ready, either new or sterilised with a proprietary agent. 3-4 inch are most suitable and plastic ones are by far easier to manage! The pot should be filled to within 1/2 or 1/4 inch of the top and tapped to level the compost. Sow medium to large seed thinly on the surface (before watering!) then add a 3-4mm layer of coarse grit. Only the very largest seed need be covered with a thin layer of compost in addition to anchor the seed. Very fine seed should be sown directly onto a single layer of coarse grit top dressing.
You can now water the pots and provided a fine rose is used this can be from overhead. Even the finest seed will be washed into intimate contact with the surface of the compost, guaranteeing available moisture as long as the pot does not dry out. In addition watering gently at this stage will avoid seed being washed to the sides of the pot which easily happens to a prewatered and often capped surface. Once watered, a final fine watering with a “copper” fungicide may insure against early fungal diseases. Now for the most important finishing touch - the label! You must note the name and date of sowing, the number of seeds sown and source may also come in handy later on. For the most organised, a notebook or even the ultimate storage medium, a computer database will help you to learn from your experiences and improve your results.

WHAT TO DO WITH THE POTS?

If cold treatment and winter sowing is indicated there is no substitute for leaving the pots “open to the elements” giving protection from only the most wet spells. A frame with removable top is ideal. Fluctuating temperatures and the action of rainfall may serve to break the seeds inbuilt dormancy as well as washing away germination inhibitors. As temperatures rise, it pays to check regularly for germination, once noted pots should be moved to a more protected environment. Spring sowings should be delayed until late March/April if the pots are to be left outdoors. Do not delay sowings too late, the relatively high late spring- summer temperatures appear to actually inhibit germination! A temperature of 60-70°C is ideal for these sowings and if space permits, an electric propagator may provide optimum conditions. Beware using a propagator too early however unless you can give a little warmth to the seedlings as they grow on. Seedlings transplanted from a warm propagator exposed to frosty conditions are likely to suffer badly or die.

TREATMENT OF SEEDLINGS

Once seedlings begin to appear, a further fine spray with copper fungicide is of use to prevent “damping off” problems. Pots should be moved to a position where they will be sheltered from strong winds, severe cold or conversely hot sunshine but still receive good light. Now we come to a much divided issue! To prick out early or not to prick out!! I must confess in the main to subscribe to the former method. There is “safety in numbers” by doing this, if one pot is knocked over or dried out , all is not lost. Seedlings may be handled very lightly by the cotyledons and gently eased out if necessary using a tiny dibber to loosen the compost around the roots. The compost mix initially described is invaluable in this respect as seedlings literally fall out with a little help. Transplanted seedlings should be grown in a well drained mix containing more nutrients than indicated in the sowing mix - more John Innes No. 2-3 or for lime haters an ericaceous mix.

GROWING ON

After an initial few days or more of gentle shade, simple netting will do, give the the youngsters more and more light and air but avoid drying wind until true leaves have formed and new healthy growth is apparent. Keep a careful eye for signs of slugs and other pests - young seedlings are particularly vulnerable, take precautionary steps with sprays/pellets if necessary. Strong plants should be ready later in the season....


BULBS FROM SEED - NOTES FOR BEGINNERS

Growing bulbs from seed is no more difficult (or easy) than growing other plants from seed. Admittedly more patience is required and the fruits of your labours take time but I can guarantee that first flower opening some three or four years on will give more pleasure than any purchased bulb! The most difficult decision is actually to decide to have a go. During the first two years or so, apart from a few leafy stems, there is little to show for your efforts. If however, you sow a few pots each year, once the initial three years are over you will have new flowering material with each new season. Why not devote 25% of your Society order to bulbous plants? It won’t cost you anything and will give you a wealth of suitable material to choose from. Erythroniums or Fritillaria (to name but two genera) costing several pounds per bulb commercially will be in flower for you in three years - given a little care and inattention during the summer!

SEED COMPOST FOR BULBS

A little more thought here will pay dividends in the long term. The basic sowing medium described on page 2 is ideal for the top inch of compost. There is little food available however and as seedlings may be undisturbed for at least a season some extra nutrient is necessary. This may be achieved by filling the bottom two thirds of the pot with a typical potting mixture. I have found equal parts JI No.2, sand and grit with a pinch of bonemeal mixed in to be ideal.

SOWING

The mandatory clean pots should be filled to within 1/2” of the top using the compost mixes described above. I prefer to use 4” pots but for small numbers of seeds 3” will suffice, some bulbous species will develop 3-4” down during the first season and the larger pot gives space for development and makes drying out less likely. Seed is sprinkled thinly onto the surface which is then covered with approx 1/8” of sowing compost. A final layer of coarse grit is added and then the pots are thoroughly watered. The majority of bulbous species are best sown during the winter and left open to the weather. Calochortus, Crocus, Erythronium, Fritillaria, Iris, Narcissus and Tulipa to name a few popular genera fall into this category. Some genera originating from warmer climates are successfully germinated from spring sowings, Allium, Moraea, Rhodohypoxis, Romulea and other South Africans are best left until spring.

GROWING ON

If all goes according to plan, slender grassy leaves will start appearing during the spring. It is not unusual for seedlings to start appearing from January onwards! At this stage the pots should be moved to a frame or under glass so that temperature extremes and watering can be controlled, a fungicidal spray applied now is advisable. During the spring to summer period pots should never be allowed to dry out but sodden conditions avoided. A weak liquid feed eg phostrogen applied occasionally will encourage strong growth. As summer approaches and the foliage starts to die back this is the time to cut down the water supply but take care that the compost does not dry out completely!

REPOTTING

Late summer (August onwards) is an exciting time (eventually!) Time now to examine pots as virtually all will be completely dormant and will not mind the disturbance ( some will be contemplating new growth soon!) With practice and experience this can be carried out the first summer but initially, I would recommend leaving the pots for two growing seasons before disturbance. The extra season will also allow any ungerminated seed a second chance to develop. Gently tap the compost out of the pot into a clean tray watching carefully for the young bulbs. Keep them to one side and repot into a potting mixture as described under “compost”. I always dust the bulbs with green sulphur before repotting as a precaution against fungal infections. Planting depth? Take note from the seed pots or as a general guide plant to a level twice the depth of the bulb!

Have fun.....


GIBBERELLIC ACID - GERMINATION OF ROSULATE VIOLAS

Inspired by the pioneering work of Norm Deno and full of enthusiasm to grow rosulate Violas, I have over the past eight years developed a treatment regime that is simple, reproducible and most important of all, successful in combining germination with a means of growing plants on! To my mind, research excepted, there is no point in simply germinating seed, the resulting seedlings must be as far as possible unaffected in their growth characteristics following treatment and be capable of cultivation to maturity.

Here is what you need and how to use it:

GIBBERELLIC ACID (GA)

Obtainable from most laboratory chemical suppliers (from which the individual may experience problems when ordering from a private address!) There are some vendors in the USA, a quick search in the back of recent "Society" bulletins should reveal likely sources. GA is a crystalline solid, which is only barely soluble in water. A number of writers subscribe to the use of "spirit", hot water or acidic pH to assist with solubility. I would advocate the use of a 0.05 to 0.1% solution and there is absolutely no need for any fiddling with the preceding "assists", just add the GA to water and leave for 24-48 hours, it will dissolve - simple as that. A golden rule is to maintain accurate concentrations, so access to a laboratory balance is vital, typically, I prepare a stock solution of 0.025g GA in 25ml of water which gives a 0.1% solution. For most treatments I use a portion of this diluted with an equal volume of water which gives the 0.05% concentration. Solutions are not stable over a long period, I tend to "batch" treat lots of seed in one operation and by doing so, tend not to store solutions for too long. A word of caution if you've read this far and intend using GA - treat solutions as you would any potentially harmful chemical - with care and respect! Wear gloves and do not use in the kitchen or leave where children / pets are around.

VIABLE SEED

The main problem is obtaining seed in the first place. We have, over the years, John Watson / Anita Flores and Jim Archibald to thank in this respect but a number of private collectors have on occasions bagged some seed. Having obtained seed, hopefully mature and free from damage, storage in a sealed container at 4'C will keep the seed alive for several years (1992 vintage V. cotyledon seed was germinated during 2001!). The strategy of GA requirement with these seeds also seems to confer an element of longevity (i.e. to cope with the possible long wait until conditions are met?) Seed must obviously be harvested at the right moment for optimum viability. I have never treated seed with any antifungal "dressings" or disinfectants and cannot comment on their value.

ABSORBENT PAPER / PLASTIC FILM

There is no need to have an excess of solution, viable seeds will absorb what they need (and plump up in the process so you can discard empty shells!) For this reason and when smaller seeds are being handled - I never add seed to solutions! All you need is 2cm square pieces of absorbent paper plus 4cm squares of thick gauge plastic film. A shallow plastic container you can seal the "seed sandwich" during the soaking treatment is also required.

SEED SOAKING WITH GA

Each portion of seed is handled as follows:

  1. Place a piece of plastic film in the container.
  2. Add a square of absorbent paper to the plastic film. (N.B the name of the seed to be treated is first written in pencil on this paper.
  3. Moisten the paper with sufficient GA solution to completely soak the paper. (I use a plastic "dropper pipette" to do this.)
  4. Add the seed to the paper.
  5. Cover with an additional piece of paper which is then soaked with GA solution.
  6. Add another piece of plastic film to complete the sandwich.
  7. The process is then repeated for as many batches of seed as you like. Layer upon layer of seeds can be built up but be careful you label the absorbent paper with the seed name!
  8. Seed is left soaking for 24 hours. The container is sealed to minimise evaporation.

SEED SOWING - POST TREATMENT

The topmost film and paper layer are carefully peeled away and the seed is transplanted onto the surface of your potting compost. I use forceps for this operation, but if very fine seed is being handled, this can be "jet washed" using the pipette from the paper onto the compost. A thin layer of coarse grit(no compost!!) is then applied and pots are placed outside. The process is repeated for each seed layer. Sowing and aftercare are exactly as described in the previous section "Alpines from Seed".

TIMING

As they say is everything. The process I have described is carried out routinely with sowings between the middle of December and end of January. Seed left outside will then normally germinate in the first warmer days of spring (end of February / early March here). If you have never germinated these Violas before, they look like "dirty" brown Lewisia seedlings! I have also had success with seed treated in early summer and obviously subjected to much higher temperatures. More work needs to be completed in this area and I suspect a variety of temperature regimes may work? (ANY DONATIONS OF SEED HOWEVER SMALL WILL ALWAYS BE GRATEFULLY RECEIVED)

Notes on the raising and care of rosulate Violas:

The 24 hour GA soak appears to "work" and longer exposure to GA would not seem to serve any useful purpose. Indeed it may make the problem of etiolation more likely. I have not yet studied the effects of shorter exposure times

0.05% or 500ppm GA solution again is a good starting point, although with most "unproven" seed, I soak a few in 0.1% solution. Seedlings generally tend to be more "leggy" when stronger solutions are used and concentrations in excess of 0.1% are definitely to be avoided (unless lower concentrations completely fail). Empirical methods involving "guessing" the concentration may give some success with experience but will always be "guesswork" and open to chance.

An important phenomenon with any population of Viola seedlings is the tendency for some to "reach for the sky" rather than others. In general the shorter stocky seedlings will make the best plants. Transplanting / repotting must always be done with care and is always a risky operation - just avoid too much physical damage to the roots etc.

The compost for sowing / potting must be well aerated and free draining. I use a mix of equal parts ericaceous compost/coarse grit/vermiculite, no scientific justification for this - it's based on my normal seed compost and they always grow well left in situ in that! Maximum light and ventilation as plants get older (if you're lucky) are essential, outside wherever possible but protected from extreme wet weather. They hate being under glass and soon reach for the sky. Care must be taken with water both above and from below in winter although I let rain and whatever fall on them when in active growth.

Rosulate violas tend to fall into two categories: as with the leggy seedlings, some plants will die (the difficult ones) and others simply thrive with no special effort, for a while anyway......... (these are the easy ones!!)


EPHEMERAL SEED

Hepaticas and certain other genera of plants produce seed deemed ‘ephemeral’. An understanding of the implications is necessary to avoid at best prolonged wait for germination or at worst – complete failure! What is meant by the term ephemeral? Well, the dictionary defines this as transient or short lived. This is suitable term as if the seed is dry stored, it may either be destroyed or go into such a state of deep dormancy to make germination unlikely or extremely slow. The message where such seed is concerned is clear – sow immediately or as soon after collection as possible! Which genera are we including in this group? Hepatica is an obvious choice and many other members of the family Ranunculaceae fall into this category: Adonis, Clematis, Helleborus and Ranunculus together with bulbous genera such as Corydalis, Galanthus and Trillium.

Seed collection

As far as Hepaticas are concerned, seed should ideally be harvested whilst green and still in contact with the plant. Timing is critical and is best judged, where exposed seed is concerned by rubbing the seed head between thumb and forefinger – if seeds detach whilst applying very gentle pressure it is ready, if it doesn’t, then wait a while longer! This obviously requires a degree of dedication and attention during late April / early May but the rewards are great.

Sowing seeds

Unless you are planning to distribute seed to friends (where a few days dry off the plant does not seem to matter) seed should be sown right away. I use 9cm pots to accommodate 30 seeds or so but larger pots can be used if desired. If I’m sowing larger quantities of seed, I simply use more 9cm pots and the proverb involving eggs in baskets springs to mind – if something untoward happens to one pot, the presence of others will ensure that the crop is not completely lost! A well drained compost (equal parts JI No 2, vermiculite and grit is recommended), seed is distributed evenly on the surface then covered with a 2mm covering of compost followed by a 5mm layer of grit. The pots are left outside exposed to all the weather – patience is required as they will not germinate until the following winter!

Germination and aftercare

If all goes well, seed leaves will be seen emerging during the late winter/spring following sowing and before you rush to prick them out - it does seem to benefit if you allow them to spend their first year of growth in the seed pot. I have found many other members of Ranunculaceae to benefit from this approach, but an exception is Hellebores which I usually prick out when true leaves have formed. Bulbous seedlings are best left for two growing seasons and during this period an occasional dilute liquid feed can be given to keep the youngsters healthy and vigorous. When the time does come to pot on the young Hepatica plants at the end of year two, one or two may be already bearing flowers. Don’t worry if they don’t, flowers will certainly be borne by the following Spring and part of the excitement is whether new colour variants will crop up amongst the youngsters? After a single growing season, plants in a 9cm pot will have a vigorous root system and be ready for planting outside. Planted in semi shade they will hopefully build up into clumps with more and more flowers each year – best of luck!


If you have come here via a search engine and would like to browse the "Alpines for the Enthusiast" website, click on the link below.....