Growing From Seed
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Seed SpoonsTM are
a great tool for planting small seeds. Available at our online store for only $2.95.
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The first step in growing from seeds
is to determine if they should be started inside or direct sown outside. Some seeds are best planted directly into the garden,
while others really should be started indoors. Most seeds can be started inside, even those which require a cold treatment
first can be"tricked" to germinate inside. Direct seeding with many annuals is a matter of choice. To determine whether you
should start seeds indoors or out consider the growing season in your area. If it is shorter than the time the plant needs
to produce flowers or vegetables then you should start indoors. Generally seeds of a manageable size are sown directly outdoors.
Really small seeds need the extra attention sowing indoors in a controlled environment provides. Some gardeners start seedlings
indoors to extend the harvest. Many vegetables and flowers will produce much earlier if started indoors. You will lose more
seedlings to the elements, insects and bad weather when direct seeding.
Growing Medium
When
starting seeds indoors, always use a soilless, pre-mixed growing medium. Such mixes are generally made up of peat, perlite
and vermiculite along with some nutrients. These mixes are for the most part free from disease, insects and weed seeds. We
also recommend you can spray your seeds or growing medium with a fungicide product such as "No-Damp" to prevent "Damping Off"
disease on your seedlings. Damping off is a disease caused by several different fungi that rot the seeds during germination
or kill the seedlings after emergence.
Sowing Seeds
We
provide sowing instructions with all our seed varieties. Some large seeds can be seeded directly into the pot where they will
grow until transplanting outdoors. For most small seeds it is best to simply scatter the seed thinly over the surface of the
soil and then cover with an appropriate amount of soil. Some seeds only need to be left on the soil surface and not covered.
After germination the tiny seedlings can be separated and transplanted into larger containers.
Soil Temperature
Most
seeds require a warm soil temperature to initiate germination. Generally, seeds germinate best at a soil temperature of 64-72
F (18-22 C). Keeping the temperature within this range can be hard, especially for seeds which take several days or even weeks
to germinate. Air temperature is generally warmer that the soil temperature, and is not sufficient enough to warm the soil.
Bottom heat from specially designed mats or cables are ideal but you can also place your containers on top of the fridge,
or radiator, etc.
Soil Moisture
When
sowing seeds inside, soil moisture is equally as important as temperature. Seeds need water to help soften the seed coat and
stimulate the root development. If your soil is allowed to dry, the germination will be delayed or, in most cases, ended.
To keep the soil moist, mix the growing medium with water, enough so that if a handful is squeezed, a small amount of water
will run out. After mixing, sow your seeds according to directions and then cover the containers with clear plastic. We really
like those "mini-greenhouse" units that come with clear domes and holding trays. You can also use sealed bags or plastic wrap
to keep your medium from drying out. If your medium begins to dry out too fast, use a water bottle which will provide a fine
mist or watering can with a gentle nozzle, as to not disturb the seeds. After germination, be sure to remove the plastic and
place plants under grow lights or in another bright light location.
Lighting
Lighting
for your seedlings is extremely important. Without sufficient light, your young plants will become tall or "leggy", which
will make them weak and easy to break. Ideally, you should use adjustable fluorescent lights when growing plants indoors.
Have your light suspended from the ceiling, or use a table top or shelf style of lighting stand to hang over the seedlings.
Your lights and the plants must be only 3-4" from the lights at all times for proper growth. You should keep your lights on
for about 16 hours a day - we recommend you use an automatic timer to turn on and off your lights. If you don't have lights,
you should grow in a bright south facing window.
Water
Watering
young seedlings can be a tricky job as you do not want your medium to dry out but you don't want it too wet either. Usually
when the top «" of the soil appears dry, you should water. Use a mister or a fine stream watering can to water seedlings.
We recommend that whenever possible to water your seedlings from below to help to prevent "Damping Off" disease. To water
from below, place your containers in a tray filled with water until the soil becomes moist (not soggy) and then remove.
Feeding
Feeding
your seedlings is important, especially if you have them in cell packs for an extended period before transplanting. You should
start fertilizing young seedlings with a mild or small dose of a balanced fertilizer such as 20-20-20 or 15-30-15. Which ever
fertilizer you use, be sure to dilute to half the strength for the first few feedings and then gradually work up to full strength.
You should feed plants at least once a week.
Transplanting Outside
Now
that you have nice healthy seedlings it is time to transplant to your garden. The most common mistake by beginner gardeners
is to rush this process. Before planting your tending seedlings outside you must subject them to a "hardening off" period.
Inside grown plants must be gradually exposed to outside conditions or they are likely to be stunted or die before they adapt
to their"harsh" environment. The process of "hardening off" requires approximately two weeks but this can vary depending on
the method you prefer to use. A couple of weeks out from your planned transplant date you should reduce the amount of water
the seedlings get. Let the soil become a bit dry-looking between watering. At least a week out from transplant time, start
exposing the plants to outside conditions. You want that first exposure to be numbered in hours. Put them out in a shady,
protected place for a few hours (say, mid-morning to early afternoon). If you live in cold climate you may want to have a
shaded cold frame available. After a couple of days of short exposure, you should be able to leave the seedlings out for the
day, still in the shade. Each day, nudge them closer to a spot that gets full sun, or uncover more of the cold frame. Within
a few days leave your seedlings fully exposed to the elements, day and night. Only then should you transplant to the garden.
Plant Hardiness Zones
Plant Hardiness
Zone Maps are often referenced when determining if a specific plant variety will successfully grow in your area. The lower
the zone number a plant has, the hardier the plant. The zone number is a general guide to hardiness. Many other factors affect
how well a plant will thrive, such as snow cover, freeze-thaw cycles and strong winds. Often there are micro-climates within
zones and even within your own garden. To find out which zone you live in, please click appropriate link below. We recommend
you only use the maps as reference and you should also check with your local agriculture department or other gardeners to
see what grows best in your zone.
Plant Hardiness Zones of USA
Plant Hardiness Zones of Canada
Seed Germination
The following data is provided by Thompson & Morgan Successful Seed
Raising Guide. This guide is out of print.
A seed is an embryo plant and contains within itself
virtually all the materials and energy to start off a new plant. To get the most from one's seeds it is needful to understand
a little about their needs, so that just the right conditions can be given for successful growth.
One of the most usual causes of failures with seed is
sowing too deeply; a seed has only enough food within itself for a limited period of growth and a tiny seed sown too deeply
soon expends that energy and dies before it can reach the surface. Our seed guide therefore states the optimum depth at which
each type of seed should be sown. Another common cause is watering. Seeds need a supply of moisture and air in the soil around
them. Keeping the soil too wet drives out the air and the seed quickly rots, whereas insufficient water causes the tender
seedling to dry out and die. We can thoroughly recommend the Polythene bag method (No. 11) which helps to overcome this problem.
Watering of containers of very small seeds should always be done from below, allowing the water to creep up until the surface
glistens.
Most seeds will of course only germinate between certain
temperatures. Too low and the seed takes up water but cannot germinate and therefore rots, too high and growth within the
seed is prevented. Fortunately most seeds are tolerant of a wide range of temperatures but it is wise to try to maintain a
steady, not fluctuating temperature, at around the figure we have recommended in our guide. Once several of the seeds start
to germinate the temperatures can be reduced by about 5 degrees F and ventilation and light should be given.
Some perennials and tree and shrub seeds can be very
slow and erratic in germination. This may sometimes be due to seed dormancy, a condition which prevents the seed from germinating
even when it is perfectly healthy and all conditions for germination are at optimum. The natural method is to sow the seeds
out of doors somewhere where they will be sheltered from extremes of climate, predators, etc. and leave them until they emerge,
which may be two or three seasons later. Dormancy, however, can be broken artificially and our section Nos. 12-16 deals with
this.
HINTS ON SEED RAISING
1. Strelitzia and similar
Do not chip or mark the seedcoat 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.
2. 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 (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 soilatid 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.
3. 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.
4. 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 plantlettes 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.
5. 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.
6. Alstroemeria; Bonsai; Clematis; Hardy
Cyclamen; Eucalyptus; Flower Lawn; Helleborus; Hosta; Primula; Iris and similar.
Sowing OCTOBER-FEBRUARY.
Sow the seeds in John Innes 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.
7. Freesia
Soak the seeds for 24 hours and sow in Levington compost, or something similar, and place in a temperature of
50-60'F. Germination can sometimes be slow.
8. 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.
9. 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.
10. 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
leafmould) lime free and very free drainage (use 1/3 grit). Never overwater, keep bulbs almost dry from November to March.
11. 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.
SPECIAL TREATMENT
12. Hard Seeds-Chipping
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 abraided 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.
13. Hard Seeds-Soaking
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.
14. 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.
15. 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 paeonies, 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.
16. Outdoor treatment
The
above mentioned methods (12-15) accelerate the germination process and help to prevent seeds being lost due to external hazards
(mice, disease, etc.) but outdoor sowing is just as effective albeit longer. The seeds are best sown in containers of free
draining compost and placed in a cold frame or plunged up to their rim outdoors in a shaded part of the garden, preferably
on the north side of the house avoiding cold drying winds and strong sun.
Recent tests show that much of the beneficial
effects of pre-chilling are lost if the seed is not exposed to light immediately afterwards. We therefore recommend sowing
the seeds very close to the surface of the soil and covering the container with a sheet of glass. An alternative method especially
with larger seeds, is to sow the seed in a well prepared ground, cover with a jam jar and press this down well into the soil
so that the seeds are enclosed and safe from predators, drying out etc.
We would also recommend you consult No.
6 which contains further practical suggestions regarding the special treatment of seeds.
