Growing kumara: It’s not as hard as you think!

Hello, fellow garden enthusiasts!

Kumara, also known as sweet potato, is a beloved staple in New Zealand gardens and kitchens! And guess what? Growing this nutrient-packed tuber is a total breeze! We’re here to spill the beans (or should we say sweet potatoes?) on how to grow kumara in your backyard. We’ll guide you through the essentials of growing kumara and highlight two products that can make your growing experience even more successful: Rootella, Mycorrhizal fungi, and Superzyme. 

Understanding Kumara

Kumara, a warm-season crop, flourishes in the temperate climate of New Zealand. With its sweet, earthy flavour and a powerhouse of vitamins, minerals, and fibre, it’s a root vegetable worth rooting for! Growing kumara demands patience, as it needs a substantial 4-5 month frost-free window to reach its full potential. This makes it an ideal candidate for planting in early spring, with a sweet reward awaiting in late summer or for early autumn harvests.

Preparing your garden bed

Kumara prefers well-draining, sandy soil rich in organic matter and humic acid. Here’s how to prepare your garden bed:

  1. Choose the right spot: Select a sunny location that gets at least 6-8 hours of direct sunlight daily.
  2. Soil preparation: Work in plenty of compost or well-rotted manure to make the soil rich and healthy for your plants. Make sure the soil is soft and drains water well. If water stays in the soil too long, it can cause the Kumara roots (tubers) to rot. 
  3. Mounding the soil: Create mounds or ridges about 30 cm high and 1 metre apart. This technique improves drainage and provides space for the tubers to develop.

Planting Kumara

Kumara grows from little shoots called slips. You can buy slips from a garden store, or you can make your own by putting a kumara (sweet potato) in water until it sprouts.

  1. Planting Slips: Add Rootella into the planting hole under slips immediately prior to planting. When the slips are about as long as your hand (15-20 cm), gently take them off the kumara and plant them in your garden. Give each slip enough space, about 30-40 cm apart, so they have room to grow.
  2. Watering: After planting, water the slips well and keep the soil moist. Don’t let it get too wet. Once they start growing, kumara plants don’t need a lot of water, but they still like a drink during dry times.

Caring for your kumara

  1. Weeding: Keep the garden bed free of weeds, especially in the early stages, to reduce competition for nutrients and water.
  2. Mulching: Apply a layer of mulch around the plants to retain moisture, suppress weeds, and regulate soil temperature.
  3. Adding beneficial fungi and bacteria: Kumara doesn’t require heavy fertilisation; instead, adding beneficial biological organisms can significantly improve growth. This is where our featured product, Superzyme, comes into play. Spray Superzyme on soil and plants in the late afternoon. 

Boosting growth with Rootella and Superzyme


Rootella contains Mycorrhizal fungi, which form a symbiotic relationship with the kumara roots. These beneficial fungi help nutrient and water uptake, promoting vigorous growth and improving plant resilience. By using Rootella immediately prior to planting, you can ensure that your kumara plants have the best start possible.

The profound impact of Mycorrhizal fungi on overall plant health, especially kumara, is truly astounding! By infusing your gardening routine with products like Rootella, Mycorrhizal fungi, you’re essentially treating your kumara tubers to an all-access pass to deluxe growth in both size and quantity!


Superzyme serves as a vital asset in your gardening toolkit. It aids in the breakdown of organic matter, facilitating the release of essential nutrients crucial for plant growth. Additionally, it offers protection against soil-borne pathogens, ensuring your plants remain healthy and robust.

Harvesting your Kumara

Get ready for a sweet reward! After about 4-5 months, when the leaves start turning yellow, it’s time to dig up your kumara. Gently use a garden fork to unearth the tubers, being careful not to poke or scratch them. Once you’ve gathered your bounty, let your kumara relax and “cure” in a warm, dry spot for a week. This makes their skins tougher and means they will keep much longer.  

Enjoy the fruits of your labour

Growing kumara in your home garden is like having your own treasure trove of delicious and nutritious gems. With the right preparation, care, and a little boost from products like Rootella and Superzyme, you’ll discover that cultivating kumara is a breeze!

More information about the products we have talked about in this blog are available in the links below and if you have any questions, simply email us at

Leave a Comment

Your email address will not be published. Required fields are marked *