How to grow Protea Seeds
Choosing the right time to plant protea seeds
The best time to sow is in autumn or spring, when the difference between day and night temperatures is about 12oC (54oF). Choose the season that gives the protea seedlings the most time to grow under favourable conditions. For example, if your summer is very hot and dry, but your winter is moderate and wet - sowing in autumn will give the protea seedlings a whole winter and spring to become strong before the harsh summer. In colder climates, it is best to sow in spring so that protea plants can become hardy before the frosts of winter.
Preparing the Soil for protea seeds
Although you can sow protea seeds in seed trays or open ground, we have best results planting each protea seed in a 500 ml plastic seedling bag. Fill the bag with a well-drained acidic soil mixture with a pH of about 5.5. You can make the mixture out of :
- 2 parts coarse river sand,
- 2 parts peat or decomposed pine needles, and
- 1 part vermiculite or perlite.
It is important that the soil mixture drains well. Water should run right through the filled tray, but the soil mixture should be such that it retains moisture and remains damp between waterings. The seeds and protea seedlings should never be allowed to dry out. The vermiculite helps retain moisture.
It helps if the soil mixture is sterilised, ridding the soil of fungus, eggs, larvae and pathogens that might harm the protea seeds or the seedlings. There are several ways to do this:
- The simplest method is to drench your soil mixture with '''boiling water''' before planting the seeds. This is best done on a flat, hard surface and has the added benefit of leveling out the soil. The drainage of the seed tray should ensure that after about 15 minutes, the soil is evenly damp. If there are any soggy patches or water pooled on the top, then your drainage is not sufficient. The boiling water kills germinating weed seeds, insect larvae, snail and slug eggs and fungal spores.
- Another '''fungicidal solution''' is Jeyes Fluid (which is saponified cresol containing a lot of phenol). You can use a dilution of 40ml to 10 liters of water to saturate your seed trays. You need to leave 2 weeks after this treatment, however, before planting your seeds, which is probably a delay you can do without. You can also use this solution on your open ground before transplanting you seedlings - but also leave 2 weeks between treatment and planting.
- A more '''organic method''' to the above with similar results would be to use plants containing phenols together with blue soap (which supplies the saponin requirement). A solution of Thyme and Sage mixed with Blue soap in warm water gives you an excellent solution with which to sterilize your soil. Instead of the blue soap you could use the roots of Soapwort. You would chop the roots up, boil them in water and cover the solution for about an hour or more, then strain it and add it to the herbal mixture.
Preparing the Protea Seeds
Pre-sowing treatment of some Proteaceae's seed increases their germination percentage considerably, and decreases the losses due to fungus infections.
Proteas, Restios and fynbos:
Dissolve one disk of Smoke Primer® in 50ml of water (at room temperature). Soak the seeds you want "smoke-primed" in the smoke-water solution for 24 hours. Then dip the seed into a solution of fungicide such as Thiram (use whatever your local nursery recommends for roses) before planting it. You can buy some Smoke Primer® from our online store.
Leucospermums, Paranomus and nut-seeded Leucadendrons:
Germination time can be decreased by soaking seeds in a 1:2 solution of hydrogen peroxide (available from pharmacies as ''Hydrogen peroxide 10 vols'') in water immediately before sowing.
Planting the Protea seeds
Plant the protea seed to a depth equal to its size and water well. Keep the seedling packets in semi-shade, and protect against mice, birds, squirrels and large insects (30% shade-cloth works well if you enclose the seedling packets completely in a frame covered in shadecloth so that creatures cannot reach the seed). Water with a fine rose spray and do not allow the seedling packets to dry out at any time.
Watering and Waiting
The quality of the water used for watering can have quite an influence on the success of your protea seed germination. Sometimes tap (''faucet'') or borehole water can be a problem and using rainwater can make a big difference to germination and later growth of your proteas. Having the pH of your water tested is a good idea. Also test for chlorine and other chemicals. Usually your local Department of Agriculture is a good place to go.
The Proteaceae are adversely affected by brackish or alkaline water and water with a high salt content. Some dam or lake water may also contain spores of the cinnamon fungus (Phytophthora cinnamomi), which is deadly to proteas. This is usually the case if it drains from an area that naturally carries this soil-borne fungus.
Our home-made seed house
The protea seedlings are suspended off the ground on a wire mesh. They are protected from mice and insects by a 30% shade cloth on all sides (and underneath).
A micro-jet sprinkler system connected to a water-computer ensures that the protea seedlings get watered up to six times a day during germination. Once the protea plants are established, they get water less frequently.
Success - Protea seedlings sprouting
The germination period varies from 1 to 3 months, depending on the species.
The cotyledons appear first, then the true leaves. Once the true leaves appear, the seedlings can be exposed to full sunlight. We keep them in the seed house longer to protect them from insect pests, and expose them to full sun only when they get planted out during the next rainy season.
Take care to leave the protea roots undisturbed during planting out. If your garden soil is well-drained and acidic, and your climate frost-free, choose a sunny spot and plant the proteas out in square holes 500 mm deep. The young protea plants appreciate some well-matured compost mixed into the soil that you fill the hole with.
Proteaceae are well-adapted to windy conditions, and like to have free air circulation around them. Mulching with well-rotted compost or wood chips helps keep down the weeds, retain moisture, cool the pproteas' roots and supply some nutrients.
If you need to keep the proteas in a pot, you must make up your own potting medium. This should be similar to the mixture you used for germinating the protea seeds, but needs more perlite or vermiculite to keep the soil well-drained and aerated and to stop it from getting compacted. Also, the protea plants will need more nutrients to survive in the pot, so increase the amount of peat or decomposed pine needles and add some well-matured compost. Ensure that the pot has enough drainage holes, and put a small layer of coarse material over them to keep them open and draining.
Since the proteaceae are adapted to nutrient-poor conditions, chemical fertilizer or manure will burn their sensitive root system. Use an organic plant food such as a fish or seaweed emulsion. Occasionally, a small amount of Ammonium Sulphate sprinkled on the soil and well-watered helps keep the soil acidic and provides nitrogen to the plants. We have found a company that makes a protea fertilizer specially formulated for proteaceae. You can buy their fertilizer from our farm store now.
Fungus poses a serious threat to proteas, and causes sudden death in some species if it attacks the roots. To avoid exposing the plants to fungal infections, keep the plants dry when it is hot. This means water the plants only early in cool of the morning - never in the evening. Also, water the plants once (or twice when they are young) a week for an hour. Shorter, more frequent, watering encourages weak root systems and fungal infection.
Things To Avoid doing to your Protea seeds
- Allow the seedlings to dry out at any time during germination - during the initial growth of fine roots they are very vulnerable
- Water germinating seedlings with a coarse spray - the droplets can disturb the soil around the seed and damage the fine roots
- Germinate proteaceae in hot-houses, with bottom heat or under glass - the heat, moisture and still air encourages fungal infection and will kill the plants
- Feed the plants with chemical fertilizer or manure - the plants have a very sensitive root system that evolved in the days when there were very few organic nutrients in the soil, and the roots are easily burned by phosphates
- Dig or cultivate around the plants - proteas may die if their fine root system is disturbed
We provide this information in good faith and cannot be held liable for success or failure of your protea growing efforts. For more information and discussion with other protea growers, visit our fynbos discussion. For a photo-essay of growing protea seeds in an eggbox, have a look at our eggbox starter kit instructions.