Cashew Nut (with red apple) (Anacardium occidentale)
Cashew nuts are the fruit of the cashew tree, an exotic tree now in many areas of the world but originating in Brazil, India and Southeast Asia – where the tree can grow and thrive in tropical climates. Cashew trees can grow fast and require less maintenance in comparison to many other subtropical plants. With the right climate and a little bit of knowledge of growing subtropical plants, growing cashew nut trees at home is not impossible.
Each cashew apple comes with exactly one cashew seed. And each cashew must be carefully taken from its shell and cleaned well. The cashew's shell, called a drupe, is toxic and can cause sickness if eaten and may cause contact skin irritation and skin burn. A careful handling of fresh cashew apple fruit is recommended.
In ideal condition and with the right climate, the Cashew will fruit within 3 years. In NZ, it will be 3+ years. The Red Apple Cashew especially are very special due to its apple that is sweet and juicy. Often enough the Red Apple part of this fruit is turned into a sweet alcoholic drink, and a perfect complement to a cold salad.
How to Get Started?
All seeds need water, oxygen, and proper temperature in order to germinate. Some seeds require proper light also. Some germinate better in full light while others require darkness to germinate. When a seed is exposed to proper conditions, water and oxygen are taken in through the seed coat. The ideal soil temperature for germinating seeds is between 20 and 30 degrees Celsius. Once the seeds germinate, the soil temperature needs to be cooler than the optimum germination temperature to support the growth of seedlings.
Cashew seeds are big and protected in a large shell. Using a small cheese grater, lightly scarify the surface of its shell prior to soaking the seeds in warm water. They should be planted flat or at an angle with the root end down and left uncovered. The mix needs to be well drained, with at least 50% perlite or coarse sand, and should be maintained uniformly moist but not waterlogged. Coco peat is another option for a good seed sowing media. Alternatively use a high-quality seed raising mix and add some light sand or topsoil. Use water misting to keep the soil moist. Another method is by placing seeds in seed growing sponges and keep them in a resealable bag and spray with water often. It may take up to 90 days for seeds to germinate, some species of plant may take even longer.
Using a heat mat will certainly increase seed germination rates but not necessary. Sometimes seeds turn to dormancy during the colder season and will sprout as soon as the first signs of spring occur. Always soak your seeds for up to 24 hours prior to planting. Apply some light fungicide solution on the seeds, pat them dry prior to sowing to avoid mould growing on seeds. Do not soak the seeds for more than 24 hours for the soft shell or skinned on seeds whilst soaking for 48 hours for a hard-shell seed is quite acceptable. Small seeds usually germinate better with some light whilst bigger seeds need to be slightly above the surface. Do not sow seeds too deep unless its hard shelled seed. If the seeds are sown too deep, they need extra energy to get to the surface for light.
Once germination occurs, gives plenty of light, remove any cover and never miss any watering so the top of soil is always moist. If the seedlings receive plenty of heat and sun, they may need watering once a day or every second day. Usually, seedlings can be transferred to another size pot once there are 2 leaves showing. The ideal size of pot is three times the size of root ball. Prepare a good quality potting mix in advance before repotting the plant. The next repotting should only be after 6-8 months once the seedlings are more established. Try not to transplant any subtropical fruit trees directly into the ground until they pass their first winter at the minimum.
Cashew thrives in all sorts of soils but preferred acidic, sandy well-draining soil. Full or partial shade is ok. Keeping the plant warm between 21-29 degrees Celsius is ideal, or they are happy in a greenhouse or growing indoors at room temperature. Plants will grow to the size of the pot, and minimal watering and fertilizing is required around winter and more often around the spring till the end of summer. Subtropical plants usually prefer well composted animal manure as fertiliser. However, an alternate feed with general fertiliser is acceptable and some seaweed or worm juice every 2 to 4 weeks during growth time will see them growing strong and healthy. Never used sheep pellets for pot plants - especially for subtropical fruit plants.
Keep subtropical plants in the warmest area indoors or in a greenhouse/polytunnel for their first 1-2 years and slowly introduce to a shaded outdoor area when the weather is good. Keep young seedlings protected from frost and strong wind.
Good luck and happy growing!
This is generic advice only and your results may vary. Laws around the purchase and use of plant seeds vary from country to country. Please be aware that germination of some seeds may be considered illegal in some countries whilst it is perfectly acceptable in another. We ask that all visitors to this website understand their national laws before ordering. We expect that you will act lawfully in your country of origin and ExoticaNZ - Plant Enthusiasts cannot be held responsible if you do not.
Germinating and growing subtropical plants require a level of skill, patience, commitment and little bit of luck. Whilst we try our very best to provide you with as much information as possible such as the growing guide, we cannot guarantee the result you desire. Note that ExoticaNZ - Plant Enthusiasts do not claim to be ‘plant experts’ in any capacity; as such we simply can’t promise you anything other than ongoing support in your subtropical plant growing journey. We ask that you do your own research and make an informed decision prior to purchase.