A mighty Proteaceae! Indigenous to the Cape Floristic Kingdom, part of the Fynbos family and exported worldwide for their magnificent, long-lasting flowers and bracts. Proteas and other plants within the Proteaceae family are not a rare sight here in the Western Cape, where they thrive growing in poor soil and receiving little to no TLC. Yet, you might still find yourself challenged to bring these local Fynbos gems to their full crowning glory. Maybe you even have had a few unfortunate plant fatalities along the way.
This is because plants within the Proteaceae family, like the Protea and other Fynbos plants, have specific growing conditions you need to adhere to for success. Don’t lose hope or give up when you grow your own Proteaceae! Because of its dwindling numbers, it is important for us as landscapers and gardeners to conserve this truly unique plant family.
How is our indigenous flora threatened?
Commercial afforestation and the development of housing estates and farms have a negative impact on the Proteaceae plant family.
Furthermore, we lose lots of these plants due to an increase in invasive alien plants. In addition, too-frequent and out-of-season fires also impact these plants.
Below are some photos of plants and weeds that are often kept in gardens for their pleasing or extraordinary looks and ornamental value. Although these plants are beautiful, they are harmful to the environment! These invasive alien plants threaten our environment & indigenous flora. If invasive alien plants take over an area, they will compete with and even completely replace native, indigenous flora.
How can you help conserve our indigenous flora?
You can do your part in conserving our wonderful indigenous Proteaceae plants. Firstly, get rid of all invasive alien plants in your garden. Some people have introduced these invasive plants in their gardens. Consequently, these plants now spread outside their natural distribution area into some natural Fynbos areas.
Furthermore, you can incorporate some Fynbos in your garden design to help conserve these fabulous plants. Luckily for you, we at Contours Landscapes wrote a how-to guide on Fynbos Garden Designing, which complements this blog.
But first, let’s look at which plants actually fall within the Proteaceae family.
What is Proteaceae?
Proteaceae are a family of plants that includes some well-known genera such as Banksia, Grevillea, and Hakea. They are native to Australia, New Zealand, and South America. Many species have adapted to dry, poor soils and harsh climates. People often cultivate Proteaceae for their showy flowers and interesting foliage. Furthermore, these species are popular in landscaping and cut flower production. With proper care, these plants can be quite easy to grow and make long-lived additions to the garden.
Proteaceae is a family of plants mainly found in the southern hemisphere. It includes:
- Leucospermums (Protea species commonly known as Pincushions)
- Leucadendrons (Protea species commonly known as the Conebush)
- Mimetes (Protea species commonly known as the Pagoda)
- Orothamnus (Rare fynbos shrub commonly known as the Mountain Rose)
- Serrurias (Critically endangered fynbos shrub commonly known as the Blushing Bride or Pride of Franschhoek)
How to grow Proteaceae
Learn to grow your Proteaceae-inspired garden with a step-by-step guide from Jessica Kruger, horticulturist:
- What climatic conditions do Proteaceae prefer?
- What soil do they prefer?
- How to plant your Proteaceae
- Mulching. The correct way you should do it
- What nutrition does Proteaceae require?
- Some basics on pruning
- How to water your Proteaceae correctly
Climatic conditions vary between all the different types of Proteaceae, but there are some requirements that they all have in common. I recommend when you choose your plants, you do your homework first. Make sure that it is appropriate for your garden or landscape’s climate. You have very little control over this, and it will be a determining factor as to whether plants survive or not.
- Full sun is a must-have. You must plant all Proteaceae in areas with as much sun as possible.
- Varieties that originate from winter rainfall regions must have good air circulation and cool nights. Moreover, they do not tolerate high humidity in summer. Due to this, they will not do well in summer rainfall regions.
- Varieties that grow in mountainous areas are tolerant of very cold conditions and even some snow. If you live in a cold area, rather choose one of these varieties.
- Some summer rainfall species are tolerant of moderate frost. Depending on the variety, winter rainfall species are usually only tolerant of light frost for short periods of time.
- All Proteaceae plants need good air circulation. Therefore, you need to take this into consideration when you plant them. Try not to overcrowd these plants.
- Proteas perform best in fairly windy conditions.
Most Proteaceae grow in nutrient-poor sandy soils. They do not do well in soils that have a heavy clay component. The general rule of thumb is that the top and subsoil should not contain more than 30% clay. If you have slightly clay soil, then you can use gypsum (neutral, does not alter PH) to slightly alter the structure of the soil by separating the clay particles. Do not use lime to do this. It will increase the PH of the soil. It is not what Proteaceae want at all! Moreover, it is toxic to them.
- A few Proteaceae which tolerate a more clay soil do exist, but there are very few of them.
- An extremely important factor is that plants from this family require acidic soil with a PH between 5-7. They will not do well in naturally alkaline soils. Hence, the reason why they do not do well in clay soils that are more alkaline.
- All Proteaceae need a well-drained soil that is well-aerated. If they are not in this type of soil, they tend to rot and develop root fungi. This leads to fatalities.
- If your soil is not perfect, you can remedy this. Dig a large hole and mix the soil that comes out of it with composted pine bark or a fynbos potting soil. This gives the plants a transitional layer and means they will not be shocked when they establish their roots.
How to PLANT your Proteaceae
Winter and summer rainfall areas have different planting seasons. In winter rainfall areas, you should plant your Proteaceae in April, May and June, when it is slightly cooler. In summer rainfall areas, you should plant in August and September – when the weather is slightly warmer and frost has passed.
- When you plant, do not use any bonemeal, phosphorus or even normal compost, as all are alkaline, and compost can contain high amounts of nitrogen, which Proteaceae are also not too fond of. Rather, as previously mentioned, plant with composted pine bark or Arnelia potting soil.
- Planting distances vary from plant to plant, but the general rule of thumb is that you should plant varieties that reach a maximum height of 2 meters and a minimum distance of 65cm apart. Leave 1 meter of space between plants that grow higher than 2 meters. When you plant varieties that grow less than 2m high, you should plant them about 50cm apart.
How to MULCH your Proteaceae
- The fact that Proteaceae tend to prefer growing in sandy soils makes it very important to implement good mulching practices. This is because the sandy soils in winter rainfall areas tend to become extremely hot and dry in the summer months.
- Mulching helps to retain soil moisture, which means the roots are less exposed and, therefore, keep cool. It also prevents weed development, which is important as Proteaceae roots do not want to be disturbed.
- If you are experiencing weeds, rather do not tug the weed out, which could disturb the plant’s roots, but cut it down to below root level to cause minimal disturbance.
- Another benefit to mulching is that, slowly, as it decomposes, it will release some natural nutrients into the soil that benefit the plant.
- Typical mulches used for these plants are wood chips, bark nuggets, gravel and crushed rock. You can also mulch using pruned and cut-up material from Proteaceae. Remember that mulches should not touch the base of the plant.
- Earthworms are often attracted to soils rich in organic matter because they feed on decaying plant material and microorganisms. They help improve soil structure by burrowing, which can enhance aeration and water infiltration.
How to WATER your Proteaceae
- When Proteaceae are young, they need a little more water – a good soaking two to three times weekly. Once they become more established, they are more drought-tolerant and water-wise. Watering is also dependent on the type of soil they are growing in. If the soil is sandy, more watering than the above is often required.
- You should water Proteaceae early in the day. If the roots are regularly wet in the evening, this can lead to fungal root infections, which can be deadly to your plant.
- Container-grown plants also require more watering than soil-grown plants, requiring a daily or every second day soaking. You should place these containers strategically. Place it in the morning sun and afternoon shade in the summertime to prevent drying out.
- Remember, if you mulch correctly, you will need to water less. This will save water and time!
NUTRITION, FEEDING AND DEFICIENCIES
- As mentioned, Proteaceae prefer to grow in naturally nutrient-poor soils. Therefore, they do not really need additional feeding.
- If you feel your plants need some feeding, keep in mind that they do not tolerate phosphorus (due to the fact that they will increase the PH) and nitrogen. This rules out, therefore, the use of chemical fertilisers.
- You should avoid normal compost, and especially mushroom compost, as they are high in nitrogen as well as phosphorus.
- The best fertiliser to use – and what we use at Contours – is Talborne 5:1:5 (16). As this is an organic fertiliser, it releases nutrients slowly, and phosphorus (the 1 in the ratio) is low. This means it will not change the PH of the soil to a higher one, negatively affecting Proteaceae.
- An additional way to feed your plants is to use pruned material as a mulch by cutting up material and adding it around the base of the plant (not touching the plant). As the organic material decomposes, it slowly releases nutrients to the plant.
- The most common deficiency experienced by Proteaceae is an iron deficiency. This deficiency crops up if the PH of the soil is higher than 6.5 (alkaline soils). This is quite common in clay soils. The most obvious sign or symptom of an iron deficiency is Chlorosis. This is where the leaves go yellow, and the veins stay green. The solution to this problem is to apply either Iron sulphate (5ml per 1L water) or Iron chelate (5ml per 1L water), which is applied over 1m2.
- Remember to make use of rain chains to catch all rainwater. Rain chains are a stylish and eco-friendly way to manage rainwater in your garden. They can help you collect rainwater for watering your Proteaceae plants while adding a decorative touch to your landscape. Learn more about how to make a rain chain for your fynbos garden.
PRUNING your proteas and other plants in the Proteaceae family.
- Pruning of Proteaceae is extremely important to extend the life of these plants and also to maintain a good shape.
- There are two forms of pruning, namely, thinning out and heading back. Thinning out is the removal of excess, diseased or dead branches at the base of the plant. Heading back is the removal of branches at any point above the base of the plant. This is especially important with branches that have already flowered.
- You should never prune your plants when they are wet. Furthermore, always use sharp secateurs when you prune.
- The pruning of Proteaceae varies for each type. We recommend that you visit the Arnelia website for more detailed tips on this particular topic.
Let’s wrap it up
In conclusion, if you struggled in the past with Proteaceae growing, we hope that these step-by-step tips will help and guide you to more successful fynbos growing in the future. Although not the simplest plants to grow, once you get the gist of Proteaceae growing, these Fynbos plants will reward you with some of the most unique and spectacular flora our world has to offer.
Remember to be on the safe side before purchasing a Proteaceae plant. Research it and make sure it will be the right fit for your garden and climatic conditions. If the rainy days do come, don’t be shy to rush off to your local retailer and find a Proteaceae gem for your garden. This is the perfect season for fynbos planting in the Western Cape!