By: Bonnie L. Grant, Certified Urban Agriculturist
Grevillea silk oak is an evergreen tree to shrub with slender, needle-like leaves and curled flowers. The Australian native is useful as a hedge, specimen tree, or container plant. In most USDA zones, the only way to keep this plant is by growing Grevillea indoors.
This plant thrives outside in areas like southern California and requires plenty of bright light and warmth. In cooler climates, container-grown Grevilleas may be brought inside in fall and returned to the patio or yard when temperatures warm in late spring.
Discover how to grow a Grevillea houseplant so you can enjoy the graceful form and colorful flowers as an attractive accent plant to your home.
There are over 250 species of Grevillea and new cultivars are introduced to nurseries and specialty plant markets every year. Smaller forms do best as container-grown Grevilleas. Grevillea thelemanniana and G. rosmarinfolia are perfect potted varieties.
The tubular curved flowers come in various hues of red, pink, and yellow. The leaves resemble some types of rosemary and have a slightly wooly coating on grayish-green foliage.
Grevillea requires temperatures above 45 F. (7 C.). It is not a frost-hardy plant and should be brought indoors where temperatures freeze.
Growing Grevillea indoors may be the only option for northern gardeners to enjoy this spectacular blooming plant. Small trees are perfect for large containers and many types of shrubs can be kept pruned to a small enough stature for other potted situations.
Caring for Grevillea plants indoors entails a good planting mix at the beginning. A combination of loam, peat moss, and sand ensures drainage, yet, some moisture retention. Grevillea plants can withstand periods of drought but perform best when kept moderately damp.
Choose a container with enough depth to allow roots to spread a bit, as the plant gets comfortable in its potted situation. The width should be at least 2 inches (5 cm.) wider than the root width of the Grevillea.
Place the container in a bright window with plenty of air circulation. Average indoor temperatures are usually suitable for growing Grevillea indoors.
Prune after the plant flowers. Cut back flowering ends to the next growth node.
Keep the soil moist in the summer but only water once a month October through April.
Use a granular plant food worked into the soil and then watered in. Feed in April and once per month until fall. Choose a low phosphorus formulation. You can tell if the formula is low by looking at the middle number in the plant food, which is phosphorus.
Watch for pests and use an organic pesticide to handle small infestations immediately.
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Grevilleas are flowering plants native to Australia, but fortunately, these lovely, exotic plants nowadays brighten up gardens and homes worldwide. Although rainforests and tropical regions are their natural environment, they can be cultivated in temperate and subtropical climates. In some regions, they need to be grown as houseplants while in warmer climates they can be grown outside. All you need to do is to pick a variety or a hybrid which will thrive best in cold climates.
Due to the various living conditions, members of the Grevilleas genus are extremely diverse in their forms, growth habits, sizes, the shape of flowers, and foliage. This genus includes trees, small shrubs and ground covers. They are mainly prized for their amazing flowering habit – some varieties can produce exotic, vividly colored flowers during the entire year!
Want to add colour to your winter garden? Grown all over Australia, grevilleas are fuss-free, native shrubs that flower, flower and flower – they really don’t know when to stop!
They come in a great range of sizes, from groundcovers and mid-sized shrubs to tall screening plants, which are perfect for privacy. Their year-round flowers are also simply irresistible to native birds and insects. The toughest thing about growing grevilleas is choosing which ones to plant!
Grevilleas will grow in most climates. However, cold and frost tolerance varies between species – always check the plant label when buying.
These beauties are sun lovers, so plant in full sun and keep sheltered from strong winds.
Grevilleas need welldrained soils. Consider building raised garden beds or, in large gardens, form beds as elevated mounds with free-draining soil. A few weeks prior to planting, dig into the soil a combination of well-aged cow manure and blood and bone. Avoid using fresh manures, as these can burn the plant roots. If growing in pots, use a potting mix formulated for natives, such as Debco Native Mix Superior or Osmocote Professional Native.
As grevilleas are sensitive to excessive levels of phosphorus, you need to use a specialised native fertiliser, such as Yates Acticote Natives or Osmocote Native Gardens. Feed them twice a year – once in spring and again in late summer
When planting, water in well with a seaweed-based solution, such as Seasol. Follow up by watering twice a week for two to three weeks, then once a week for about four weeks. Water more in hot, dry weather and less in winter or cooler, moist conditions. After the plant is established, it can withstand periods of drought but, if watered during dry periods, it will grow and flower better.
A layer of mulch over native garden beds will help retain soil moisture, suppress weeds and protect roots. Use organic mulch such as compost or lucerne and spread about 50mm deep around the plants. Take care not to pile mulch around the stems, leaving a clear ring at least 10cm across.
You can tip prune during the flowering months to encourage more blooms. If the plants are looking a little leggy and tired, cut back by about one-third during the warmer months, ideally after a heavy flush of flowers, to stimulate bushy new growth.
Propagating a new ginger plant all begins from the root of the plant. The roots have small nodules or “eyes” (think of a potato) that produce new growth.
Much like when planting a potato, slicing a portion of the ginger root can create a new plant. That is, as long as it has a nodule or two for sprouting.
There are several option for starting your own ginger plant, some of which work better than others. The most common is by purchasing ginger root straight from a nursery or greenhouse, or by taking a cutting from the roots of an existing ginger plant.A new ginger plant will grow from a live ginger root. New shoots sprout from nodules along the root surface, although the process can take a while to begin.
One of the great things about ginger is that it can be continually grown from cuttings. All without ever harming the original stock!
Although you can attempt to start ginger plants from roots purchased from your local grocery store, it can be difficult.
For starters, many vegetables and herbs heading to a grocery store go through a heat process to kill off pathogens. And the process can often render the ginger root unable to sprout new growth. The other issue is that store-bought ginger can be treated with chemicals, and is often older and less likely to sprout.
Not only is the foliage of a ginger plant beautiful, so is its bloom. Plants can be grown continually from new cuttings from the root of an existing plant.
If you do want to try the store-bought ginger route, be sure to purchase organic ginger that has not been eradicated or processed.
Of course, you can also purchase a living ginger plant right from the start too! Product Link : Live Ginger Plant
Ginger is a heavy feeder, and requires fertile, well-drained soil to grow and develop maximum size and flavor. When planting or transplanting, always use a good-quality potting mix. Without good soil and drainage, the roots of ginger can easily rot and kill of the plant.
Not only can ginger be grown indoors, it can also be moved outdoors in the summer to decorate porches and patios. In addition, many even plant it directly in their flowerbeds for added interest and fast growth.
Choose a container that will allow for adequate root growth. Ginger needs a lot of space to develop. Pots that are least 8 to 10 inches in diameter work best. They allow for enough surface area for the roots to develop full flavor.
Cut your ginger before planting, being sure to allow for a few nodules on each root that will be planted. Set the ginger aside out in the air for a few days after cutting to allow the cutting area to scab over a bit.
Next, fill your pot with about 4 inches of potting soil in the bottom. Then, set your ginger root cuttings down into the soil, making sure the eyes or nodules are pointing up. Press the ginger root into the soil slightly to set it into place.Press the ginger root into the soil at the bottom of the container before covering it with additional potting soil.
Next, cover the ginger root with more potting soil, adding enough that the top of the root is under a 1/2″ of soil. To finish, slightly moisten the soil, and let the waiting begin!
Unfortunately, ginger isn’t in a hurry to sprout. In fact, it can take upwards of 8 to 10 weeks to see the first sprouts pop through the soil. The key to success is all in keeping the soil moist and warm to encourage sprouting.
One way to do this is to cover the top of the pot with plastic or plastic wrap to help retain moisture and humidity in the soil and pot. Allow a few small holes for ventilation, but keep the moisture dome in place until the ginger root begins to sprout up through the soil.
It can take up to two months for ginger to first sprout through the soil. Keeping the plant in a warm, humid place will help to speed up the process.
Once it has come through the soil, simply remove the plastic lid or wrap. Then, place the plant in a warm location that receives plenty of indirect lighting.
In it’s natural setting, ginger grows best in shadier locations. By mimicking those same lower light level conditions indoors, it will help the plant grow strong and healthy.
When it comes to long term care, proper watering and fertilizing are big keys to success. Ginger should be watered often enough so that the soil never dries out for more than a day at the most.
Slightly moist soil is best for growth, but be careful not to over water and saturate the soil. Overly wet soils will rot the plant’s roots if they are sitting in heavy moisture constantly.
As mentioned, ginger is a heavy feeder, so fertilizing is a must for promoting strong growth. Fertilize every 4 weeks with a light solution of an all-purpose, well-balanced organic fertilizer. This will give the plant plenty of nutrients to grow to full size.
You can harvest ginger as a young, tender root, or allow it to grow to full maturity and harvest with a more robust flavor.
An entire root of fresh ginger ready to use in the kitchen! Once you have a ginger plant in the house, you can continually grow new plants from the existing roots.
Young ginger will have a lighter, more mild flavor. It is usually so tender, peeling is not needed. To harvest young ginger, gently lift the roots from the pot and carefully slice off a section. Place back into the pot immediately, covering with soil to keep the remaining roots and plant healthy.
To harvest more mature ginger, allow the plant to continue to grow until the roots have filled out, and the skin has toughened up. Mature ginger will require peeling before using, but the flavor is deeper, spicier, and more complex than young ginger.
To keep the growing cycle going, you can slice off a portion of the mature ginger to restart a new plant all over again – keeping the rest to use as needed.
Here is to growing fresh ginger indoors this winter and beyond! For more great plants to grow indoors, check out our entire Houseplant category on the blog.
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Grevilleas are generally a fairly hardy plant.
Their native Australian genes mean they are generally drought and cold/frost tolerant. For the most part they like full sun or partial shade and they prefer well-drained soils.
Avoid soils with a pH of more than 7 grevilleas prefer to get their roots down into more acidic soils.
In less well-drained soil creating a raised planting area will aid drainage and help keep your grevillea happy.
Grevilleas don’t need much fertiliser –perhaps a small helping of native plant fertiliser or blood and bone in the early spring.
But do make sure you avoid fertilisers containing phosphorous, as this will cause discolouration of the leaves. Resist the temptation to feed fresh manure around grevilleas this can burn the roots.
During the flowering season cut back spent flowers to encourage more prolific flowering.
Pruning will nearly always help your grevillea to develop dense foliage and a generous flower display. A general rule of thumb would be to prune your grevillea back by a third after the main flowering season is over.
If your grevillea groundcover is getting really straggly you can tidy it up with a good hard prune but some grevillea varieties won’t survive if you cut right back into the old wood and completely remove all the new growth.
It is a good idea to stake taller grevilleas for their first year so that they can form a really strong root system.