Nicking or Scarifying | Soaking | Stratification | Double dormancy | In plastic bag | Coffee | Cover glass | Begonia | Clematis | Cacti | Clivia | Ferns | Lilies | Strelitzia |
1. Nicking or Scarifying
Nicking or Scarifying: some seeds have a very hard seed coat which makes it difficult for them to take up moisture. Chip the seed with a sharp knife at the part which is furthest away from what appears to be the eye of the seed. Or rub lightly with sandpaper. If the seed is small, then rubbing a small amount of seed between two pieces of sandpaper or emery paper (gently!) will work (this is called scarifying). You may wish to look for seed which has already been treated in this manner, although not many companies do this.
Some seeds, e.g. Sweet peas, lpomaea etc., have hard seed coats which prevent moisture being absorbed by the seed. All that is needed is for the outer surface to be scratched or abraded to allow water to pass through. This can be achieved by chipping the seed with a sharp knife at a part furthest away from the 'eye', by rubbing lightly with sandpaper or with very small seed pricking carefully once with a needle etc. Some of our geranium seeds have already been treated in this way when you receive them.
Soaking: this can be of benefit in two ways. Besides softening the seed coat, it can also help to leach out chemicals present in the coat which could inhibit germination. Soak seed for 24 hours in water which begins at a temperature which is hot to the hand. As each seed swells up, remove and plant before it dries out.
Soaking is beneficial in two ways; it can soften a hard seed coat and also leach out any chemical inhibitors in the seed which may prevent germination. 24 hours in water which starts off hand hot is usually sufficient. If soaking for longer the water should be changed daily. Seeds of some species (e.g. Cytisus, Caragana, Clianthus) swell up when they are soaked. If some seeds of a batch do swell within 24 hours they should be planted immediately and the remainder pricked gently with a pin and returned to soak. As each seed swells it should be removed and sown before it has time to dry out.
Stratification (cold treatment): some seeds need a simulated winter to break dormancy. Use a tiny plastic bag with a small amount of dampened (not soaking!) sand. Add the seeds and place in refrigerator (not the freezer!) for the required amount of time. Check them from time to time to insure they don't dry out. Most seeds which require stratification also require light to germinate, so surface sow by just gently pressing the seed into the soil but make no attempt to cover with soil.
Stratification (cold treatment) Some seeds need a period of moisture and cold after harvest before they will germinate-usually this is necessary to either allow the embryo to mature or to break dormancy. This period can be artificially stimulated by placing the moistened seed in a refrigerator for a certain period of time (usually 3- 5 weeks at around 41 F). With tiny seeds it is best to sow them on moistened compost, seal the container in a Polythene bag and leave everything in the refrigerator for the recommended period. However, larger seeds can be mixed with 2-3 times their volume of damp peat, placed direct into a Polythene bag which is sealed and placed in the refrigerator. Look at seeds from time to time. The seeds must be moist whilst being pre-chilled, but it doesn't usually benefit them to be actually in water or at temperatures below freezing. Light also seems to be beneficial after prechilling and so pre-chilled seeds should have only the lightest covering of compost over them, if any is required, and the seed trays etc. should be in the light and not covered with brown paper etc.
4. Double dormancy
Double dormancy: Some seeds require more than one cold period or else a combination of conditions in which to break dormancy.
Double Dormancy Some seeds have a combination of dormancies and each one has to be broken in turn and in the right sequence before germination can take place; for example, some Lilies, Tree peonies, Taxus need a three month warm period (68-86'F) during which the root develops and then a three month chilling to break dormancy of the shoots, before the seedling actually emerges. Trillium needs a three month chill followed by three months of warmth and then a further three month chill before it will germinate.
5. In plastic bag
Extremely small seeds should be sown on the surface of a wet paper towel which is placed on a saucer or other flat dish. Cover the saucer with a food storage bag and twist tie the end to make a plastic tent. Don't put this in direct sunlight, but do put it in a bright spot. As the seeds begin to sprout, prick them off and plant. Or, you can place the potting medium into a plastic bag and sprinkle the seeds on the moist soil and twist tie the end of the bag. Cleaned meat trays from the market make good shallow containers for this too using either the paper towel or soil.
For more delicate seeds A method which has proved useful for not only small delicate seeds but for a wide range of types is the Polythene bag method. The seeds should be sown on the surface of the moist compost, covered to their recommended depth if necessary and the container is then placed inside a Polythene bag after which the end is sealed with an elastic band. The bag should 'fog-up' with condensation within 24 hours and if this does not occur place the container almost up to its rim in moisture until the soil surface glistens, then replace in the bag and reseal. The bag is not removed and normally no more watering is required until the seeds germinate. However, it is wise, if left for a long period to check the compost occasionally. The seed container, bag etc. should be placed in a well lit place with a steady temperature. As soon as a fair number of the seedlings emerge remove the polythene bag, lower the temperature a few degrees and provide plenty of light, but not bright sunshine, to ensure that sturdy seedlings develop. It is also helpful to spray the seedlings occasionally for the first 14 days.
BANANA; COFFE; CYADS (and similar plants); MINI-ORANGE; PALMS; TEA: These plants are highly erratic in germination and can require several months. Seeds must be soaked for a minimum of 2 hours in warm water before sowing. Sow in compost especially designed for these plants and place in the dark at 75ºF. Keep compost moist at all times, but not wet. Check regularly and once in a while, dig around in the compost with a small knife or similar tool. Sow seeds just below the surface of the soil. Should a seed produce a root and no shoot, prick it out immediately and pot it in a 3 to 4" pot. It should produce a shoot then. When ready to be potted, Cycads prefer a planting medium of half sand and half peat. Tea requires the same treatment as the others but prefers a temperature of 60-65ºF. After soaking, remove the parchment-like on the coffee seeds with your fingernail before planting.
Palms; Banana; Coffee; Mini-Orange; Tea; Cycads and similar All these items can take several months to germinate and are very erratic in germination. Soak for at least 2 hours in warm water before sowing. (After soaking the parchment shell on the Coffee seeds should be removed with the fingernail). Sow in Levington or Arthur Bowers [note: a peatmoss based mixture]. Compost and place in the dark in a temperature of 75 degrees F, keeping the compost moist at all times, but not wet. Inspect regularly and occasionally dig around in the compost with a penknife. We normally sow our seeds just below the surface of the soil as we have found that sometimes they make a very vigorous root without producing a shoot at all. If you find a seed with a root then it should be excavated and potted up into a 3-4'' pot immediately when it will produce a shoot. Cycads prefer to be potted up into a compost of half sand and half peat. The Tea requires the above treatment but in a lower temperature of 60-65 degree F.
7. Cover glass
BEAD PLANT: Use a good draining medium free of fertilizer. Equal parts moss, peat and sand makes a good medium. Barely cover the seed and cover with glass or clear plastic. Place container in temp of 65-75ºF. Since too much condensation can damage the young seedlings, be sure to lift glass or plastic and remove daily. When the first seedlings are spotted, remove cover and place in bright spot, but not in direct sunlight. Plant up seedlings as soon as possible in a mixture of ½ peat and ½ sand. Keep moist and in a shaded spot until well
Nertera Granadensis (Bead Plant) We recently found that this subject requires a well drained compost which is completely free from fertiliser (e.g. moss peat and sand in equal parts). Sow by barely covering the seed and place a sheet of glass over the container, and leave in a temperature of 65-75'F. Turn the glass daily as excessive condensation can kill the young seedlings. On germination the seedlings look very thin and spindly and the glass should be removed almost immediately and the seed container moved to a well lit but not sunny position. Prick out as soon as possible into a compost of 50% pure peat and 50% sand. Keep moist and shaded until established.
BEGONIA; BROMELIADS; CINERARIA; CALCEOLARIA; DROSERA; CHRISTMAS CACTUS; LIVING STONES; MECONOPSIS; NEPENTHES, RUBBER PLANTS; SAINTPAULIA; SARRACENIAS; STREPTOCARPUS; TIBOUCHINA: Surface sow on compost that is quite moist. Cover container with glass or clear plastic and place in diffuse light at temperature of 65ºF. When seeds begin to germinate, remove covering gradually. Seeds can also be spread on damp paper toweling or blotting paper and covered with plastic on windowsill which gets good light. Do NOT place in direct sunlight. Keep paper moist until seedlings are large enough to prick out and plant in small pots. For Drosera, Nepenthes, and Sarracenias make sure medium is both moist and free draining. Use NO fertilizer, but compost should contain some sphagnum moss.
Bromeliads; Cineraria; Calceolaria; Insect Eaters (Drosera, Nepenthes, Sarracenias); Living Stones; Meconopsis; Rubber Plants; Saintpaulia; Streptocarpus; Tibouchina; Xmas Cactus; Begonia and similar. These seeds should be sown on the surface of the compost and not covered. The compost should be quite moist and we would recommend that you cover the seed container with a piece of glass or clear plastic and leave in a temperature of approximately 65 degrees F in a position which receives diffused light. Once some of the seeds have germinated air should be admitted gradually otherwise the seedlings may damp off. Alternatively the seeds can be sown on to moist blotting paper or kitchen towel placed in a saucer. Cover with a transparent cover and place on a windowsill which receives plenty of light, but not direct sunlight. Keep the blotting paper wet at all times and when the tiny seedlings are large enough to handle prick out into small pots. If the INSECT EATERS are sown using the first method described the compost requires to be both moist yet free draining. Use only pure peat with no fertiliser added to which sphagnum moss should be added if available.
ALSTROEMERIA; BONSAI; CLEMATIS; HARDY CYCLAMEN; EUCALYPTUS; HELLEBORUS; HOSTA; PRIMULA; IRIS: Between October and February, sow in compost and just barely cover. Place container in cold frame. Protect from predation by mice. Leave till spring. Keep medium moist but not wet. In spring bring containers into greenhouse or place on a well lit, but not sunny, windowsill. Keep moist. If seeds do not germinate, keep them in cool, moist conditions through summer and place back in cold frame in late fall. Once seeds do begin to germinate, remove them individually almost at once and set in pots. An alternative method is to sow between March and September in a compost designed for these plants. Place the container in a plastic bag and place in refrigerator for 2 to 3 weeks. Remove and place in cold frame. If some should germinate, plant up when large enough to handle. The rest of the seeds will remain dormant until the following spring. Alstroemeria, Clematis, Hardy Cyclamen and Helleborus can take up to 18 months to germinate.
Primulas can also be sown in a pre-moistened peat-based compost. The seeds should not be covered if using this method. Cover container with glass or plastic and place in the dark at 60ºF. If the temp goes over 65º, germination will not occur. Once seeds have begun to germinate, sprinkle a small bit of compost over them. When the leaves appear, move container to a place that is well lit (not direct sunlight) and has a temp of 55ºF.
Alstroemeria; Bonsai; Clematis; Hardy Cyclamen; Eucalyptus; Flower Lawn; Helleborus; Hosta; Primula; Iris and similar. Sowing OCTOBER-FEBRUARY. Sow the seeds in John Innes [note: a loam-based mixture] seed compost, covering them with a thin layer of compost. After watering place the seed container outside against a North wall or in a cold frame, making sure they are protected against mice, and leave them there until the spring. The compost should be kept moist but not wet at all times, and if the seed containers are out in the open then some shelter has to be given against excessive rain. In the spring bring the seed containers into the greenhouse, or indoors on to a well lit but not sunny windowsill and keep the compost moist. This should trigger off germination. If the seeds do not germinate in the spring keep them in cool moist conditions throughout the summer. As each seed germinates we would recommend that you transplant it almost immediately into its own pot. Sowing MARCH-SEPTEMBER. Sow in John Innes seed compost, or something similar, and place each container in a polythene bag and put into the refrigerator (not the freezer compartment) for 2-3 weeks. After this time place the containers outside in a cold frame or plunge them up to the rims in a shady part of the garden border and cover with glass or clear plastic. Some of the seeds may germinate during the spring and summer and these should be transplanted when large enough to handle. The remainder of the seeds may lay dormant until next spring. Germination of some items, particularly Alstroemeria, Clematis, Hardy Cyclamen and Christmas Rose (Helleborus) may take take 18 months or more. An alternative method for growing PRIMULAS is to sow in a peat based compost which has already been moistened and do not cover the seed. Cover the container with a piece of glass or plastic and grow in the dark in a steady temperature of 60F. This is quite adequate and over 65'F germination will be inhibited. When the seeds start to germinate sprinkle a thin layer of fine compost over them and when the seed leaves come through this, move the box to a well lit place with a temperature of 55'F. At no time should the seed box be in full sun. Hardy Cyclamen have been found to germinate best in total darkness at around 55-60'F. We have had good results with the following method. Place the seeds between two pieces of damp filter paper, Kleenex tissue, etc., then put into a polythene bag and place this into an opaque container in order to exclude all light. Inspect the seeds after a month and remove and prick out as the seedlings appear, returning the ungerminated seeds to total darkness.
CACTI: Sow in compost. Furrow should be very shallow and seeds must not be completely covered. Water from beneath. Cover container with glass, then a piece of dark paper (as from paper bag) or a piece of black plastic. Position in a dark place, maintaining a temperature of 70-75ºF. Keep moist. When germination commences, move to a position that receives indirect light (do not place in sun). Allow good air flow and continue watering from beneath. When seedlings begin to overcrowd the container, pot up. During the first winter season, make sure to keep plants warm, but do not allow to get too dry. From second year onward, keep on the dry side during the winter months.
Cactus and similar Make very shallow furrows in compost with a plant label and sow in these. No seed should be completely buried. Water from beneath and cover with glass and brown paper or black Polythene. Place in a dark position in a temperature of 70-75F and keep moist. On germinating move to a light but not sunny windowsill, give plenty of ventilation and water from beneath. Pot up when they begin to overcrowd. During the first winter only keep warm and do not allow to get too dry. If it is not possible to grow warm then keep them drier. Subsequent years keep relatively dry through the winter. Can be planted outside, plunged to the rim, all summer if required.
CLIVIA (and similar plants): These seeds should be sown immediately upon receiving them. Sow in a peat-based compost to a depth of ½", then water and place in a dark environment at a temperature of 65-70ºF. Signs of germination should appear in 3 weeks.
Clivia and similar Sow these seeds immediately on receipt in Levington or a peat based compost, covering with a 1/2 " compost. Water and place in the dark in a temperature of 65-70'F. Germination should occur within 3 weeks.
FERNS: Fern spores require a fine film of moisture over which to move in order to complete the reproduction process. A good peat compost, pressed down firmly, must be used and kept a great deal more moist than normal. The spore should be sprinkled close together on the surface. Cover container with a piece of glass and move to a spot of diffused light. (Should not be in darkness). Compost must remain moist at all times. Germination begins with the appearance a film of green jelly on the soil surface. The process can take anywhere from 1 to 5 months before the plantlets appear.
Ferns (Garden and Indoor) The fern spore needs a fine film of moisture over which to swim in order to complete the process of reproduction, therefore a good peat compost, such as Levington, ought to be used pressed down very firmly and which is a lot more moist than one would normally have it in order to provide the moisture film. The spore (seed) should be sprinkled close together on the surface of the soil and not covered and the container should be covered with a piece of glass and placed in diffused light, but not darkness. It is essential to ensure that the compost remains moist at all times. Germination which commences with the appearance of a film of green jelly over the soil can take anything from 1 -5 months.
You may wish to try germinating the fern spore on blotting paper which is placed in a saucer and kept moist at all times. A transparent cover is inverted over the saucer and the whole lot placed in a well lit but not sunny position. You can actually see the fern spores developing and when you can see small plantlets appearing along the jelly the blotting paper should be lifted and placed on the surface of a container of Levington compost and watered well. It should then be covered with a transparent cover which can remain there until the plants are quite large.
LILIES: Some lily seeds require a double dormancy (a period of warmth followed by a period of cold). Sow seeds in a flat in summer. Place in a plastic bag and place in fridge for the winter, or cover with a piece of glass and set in cold frame. Seeds should germinate in spring. An alternative method is to place seeds in a jar with a ibt of peat kept moist, but not saturated. Screw lid on jar and place in a warm spot (70-75ºF) for 3 to 4 months. Check regularly. If any have sprouted, prick out and pot up. After the period of warmth, place in fridge for winter. The majority of the seeds that will germinate, will do so when returned to springlike warmth. Soil should be peaty and lime free with good drainage. Once bulbs are established, keep nearly dry during the winter months. Lilies resent being too wet.
Lilies Successful germination of seeds of some lilies requires a period of warmth followed by one of cold. Method 1. Put seeds in a screw top jar in moist (not wet) peat and keep at 70-75F for 3-4 months. Inspect regularly, any normal seedlings (that is having root and seedling leaves) should be pricked out as they germinate. Any seeds which produce roots but not seedling leaves, sow in a pan and keep at 32-40'F for 3 months. Seed leaves and normal growth will follow. Method 2. Sow in a pan in summer (warm spell); put in a frame (or outside covered by a piece of glass) for the winter. Seeds will germinate in spring. Soil Humus rich (peat or leaf mould) lime free and very free drainage (use 1/3 grit). Never over-water, keep bulbs almost dry from November to March.
STRELITZIA: Remove orange tuft and soak for a minimum of two hours up to overnight and as long as 3 days (change water daily). Sow seeds in moist sand, pressing them into the sand till only a small part is visible. Grow in a temperature of 75ºF in the dark and make sure the sand remains moist. After 7 days, inspect container once a week. As soon as signs of germination appear, remove the germinating seed and pot up in a medium composed of half peat and half sand. As soon as potted, make sure there is plenty of diffuse light and good ventilation to avoid fungal problems. Germination can occur as early as one week and as late as 6 months. Extremely irregular in habit.
Strelitzia and similar Do not chip or mark the seed coat at all but merely remove the orange tuft and soak for up to 2 hours, or even overnight. Sow the seeds in moist sand, pressing them into the sand until only a small part of the black seed is visible and grow in a temperature of 75 degrees F in the dark and ensure that the sand always remains moist. From 7 days onwards inspect the container once a week and as soon as any bulges, roots or shoots are seen remove the germinated seed and pot up in a compost of half peat and half sand. We find that Strelitzias often produce a root without a shoot and we have also found that the young shoots and roots are susceptible to fungal attack. Therefore as soon as possible pot up and provide light and fresh air. Germination can start within 7 days and carry on for 6 months or more.