Hellebores are temperate climate plants. They like a cool to cold Winter and not too much humidity.
So Hellebores can be grown anywhere in Tasmania and Victoria. Temperate areas of South Australia, including Adelaide and surrounds, are fine for Hellebores. In NSW Hellebores can be grown in coastal areas up to about Newcastle. Coastal areas further North than this will be too humid for Hellebores. So Hellebores can be grown in Sydney and will be particularly at home in the Southern Highlands and Blue Mountains. In inland areas of NSW Hellebores enjoy the cold Winters and can be grown well in non-arid areas from Wagga, Canberra through Bathurst, to Armidale. In Queensland Hellebores can only be grown in higher altitude Southeastern inland area such as Stanthorpe, Warwick and Toowoomba.
Planting Hellebores in the correct position in the garden is the key to growing them successfully.
In the wild Hellebores are found in and around deciduous woodland. They are adapted to having shade for most or all of the day in Summer (when the trees are in leaf) and good light if not full sun over Winter (when the woodland canopy is bare). So while it is true that Hellebores are ‘shade plants’, it is deciduous rather than year round evergreen shade that they want. Indeed planting Hellebores under large evergreen shrubs and trees is the most common mistake made when planting Hellebores. If too dark under evergreen shade in Winter, Hellebore will not grow and flower to their potential.
So planting Hellebores under or near deciduous trees and shrubs is the best tip. If that is not available then a position which gets some light from the low Winter sun, but shade in Summer is best or morning sun and afternoon shade.
The easiest and most adaptable Hellebores are the Helleborus x hybridus varieties. They tolerate less than ideal drainage, heat, humidity and pets better than other Hellebores. They are available in a wide range of colors as well. Some colours are more vigorous than others in the H. x hybridus range. The single and double whites,
Best type of fertilizer for Hellebores is a ‘complete’ one. By complete we mean a fertilizer which has all three major elements plants need for nutrition: nitrogen (N), phosphorous (P) and potassium(K). Most commercially available fertilizers are ‘complete’ and have N, P and K present. Just check on the pack. Blood and bone is not complete (no K). Hellebores will need the K for flowering.
So liquid, controlled release, powdered, organic or otherwise, the main thing is the ‘complete’ bit. And applying it at the right time of the year: mid autumn through to end of winter is best. Hellebores like plenty of feed, so there is little risk of overfeeding. We use a controlled release fertilizer in the nursery. This can be a good way to go in the garden as well, just one application in Autumn is all that is required.
In addition to the complete fertilizer Hellebores will also appreciate an annual light dressing with Dolomite lime which provides calcium and magnesium which Hellebores also enjoy. Same timing as for the fertilizer.
Although removing the old foliage of Hellebores is not essential, it is a good practice. By autumn the foliage of many Hellebores will be looking a bit past its best and the plants will be about to put on new seasons growth. For Helleborus x hybridus this will see firstly new flower stems followed by new foliage.
When signs of new shoots coming up from the base of the plant are evident, typically during autumn with the exact timing varying a bit from year to year, then the time is perfect to cut off all the old foliage, before flowering. Cut it all off right down to the base, leaving any nice new growth.
This will have the benefit of showing off the flowers better, tidying up the plant and getting better air movement through the plant over Winter, preventing possible fungal problems.
It is important to note that the above comments apply to the most common type of Hellebores, the low clump forming Helleborus x hybridus. For the taller growing species such as Helleborus argutifolius, Helleborus foetidus and Helleborus x sternii, which flower a bit differently to the hybrids, the timing is different. For these species the old flowering stems get removed after flowering, typically in mid to late spring when some new shoots are evident around the base of the plant.
The most common reason why hellebores don’t flower well is a lack of light during winter. If they are planted in heavy shade in winter, typically under evergreen trees or large shrubs, they won’t flower as well. You will get best flowering from your Hellebores if they have full sun or as near to it as possible during the winter months. Other possible causes can be a lack of nutrition – fertilise them in autumn. Also if they are planted in very sandy soil they can struggle to thrive and flower.
Oh and the smaller one year old seedlings we sell through mail order or at various Plant Fairs during the year will usually not flower until winter the following year – so just be patient with those ones.
If the Earth were ever to be struck by an asteroid large enough to wipe out all life on the planet, my personal view is that a small but determined population of aphids (and maybe a few cockroaches) would probably survive. They are that kind of creature. In the absence of armageddon you will need to spray them - with extreme prejudice. While the choice of what to spray them with is up to you – the method used is probably more important.
If you want to be less toxic on the environment you can use the contact action pyrethrum/garlic/chilli type sprays which are readily available at nurseries and hardware stores. If you are happy to be a bit less wholesome then you can try systemic sprays such as Confidor which will last a bit longer. Either way it is most important to get good coverage with your spray, especially on underside of foliage which is where the aphids mostly reside. Secondly you will need to spray several times to get on top of the aphids – probably three sprays a week
apart with the contact type sprays. And then keep an eye on the plants to make sure the aphids don’t make a triumphant return.
I reckon it is best to invest in a 2-5 litre pressurized spray unit with a hose and wand. This will allow much easier access to the plants than using the little hand pump packs. It will also result in more spray on the plants and less on you and you can buy the spray concentrates to mix up and save money.
Hellebores can be grown in pots. All of our stockplants at the Nursery (some we have had for up to 20 years) are grown in pots. However growing Hellebores in pots takes a bit more care than planting them out in the ground.
Firstly, most Hellebores have quite extensive root systems. This makes them quite drought proof in the ground once they have become established. However in pots this extensive root growth creates challenges. After two or three years of growth Helleborus x hybridus varieties will need to be in quite large (20 to 30 litre) tubs to hold all that root mass.
Do not pot up a Hellebore in a small tube straight into a very large pot. Hellebores need to be gradually staged up from smaller to progressively larger pot sizes in several steps. Our 75mm tube size that we sell mail order and at Plant Fairs should be potted up into a about a 1.5 litre (or 150mm diameter) pot size. Once that pot is filled with roots, move it up to a 4 to 5 litre pot and then up to the final 20 to 30 litre pot. This might take a year or two.
The caulescent Hellebore species and hybrids, including H. argutifolius, H. x sternii, H. lividus and H. foetidus are not suited to growing in pots. They are very fussy on drainage and it is too easy to overwater at the wrong time and lose them. The best variety for pots is Helleborus x hybridus.
If grown in pots, Summer watering as required and autumn feeding with a controlled release fertilizer such as Osmocote becomes more important.
When Hellebores flower out of season, for example over Summer, the flowers will not be as good as for normal Winter flowering. Sometimes they can be a different colour altogether.
If you have quite a few Hellebores you will find that each year a few will ‘get a bit confused’ and flower at the wrong time. This can be caused by unusual weather conditions or a plant settling into a new spot. Best to cut off these unseasonal flowers ASAP, and ignore completely what they look like. When the plant does eventually settle into flowering in Winter or early Spring, the flower will be a much better indication of the true flower colour and form.
In the wild Hellebores grow in places which can experience quite a bit of snow, ice and other inclement weather over Winter when the Hellebore are also in flower. To protect the internals of the flower and allow successful pollination and development of seed the Hellebore rather sensibly has a tendency to have the flowers hang downwards. Upward facing flowers might work in Summer but at -10 degrees C in Winter in the Balkans it can be a recipe for reproductive disaster.
The extent to which the flowers hang downwards rather than outwards does vary between different Hellebores and can also be affected by climate. In our own breeding we try to select for more outward facing flowers. However, all is not lost even if the flowers of a Hellebore do face down as the backs of the flowers are generally the same colour as the inside and provide a good display anyway.
If I plant my nice new Hellebores with the ordinary ones I have in the garden, will they ‘revert’ to the same colour as the ordinary ones?
No. The belief that somehow Hellebores will change their flower colour due to the presence of other Hellebores is a myth. Silly one too. Without getting into too much detail it seems to be based on i) a fundamental misunderstanding of the process of ‘pollination’ by bees and ii) observations about Hellebore flower colour changing over time.
Hellebores rely on bees for pollination. This involves the transfer of pollen from one flower to another flower on either the same or a different plant. After pollination the ovaries of the flower which has received pollen will be fertilized and will eventually produce seed which will drop from the plant and germinate into a new plant. Pollen from the anthers of a white flowered Hellebore being placed on the stigmas of a reddish flowered Hellebore may produce seedlings which could be pink flowered. However, the process of pollination does nothing to change the genetic makeup and hence flower colour of the original two parent plants.
Observations of Hellebores ‘changing’ flower colour are based on reality, but do not involve the plant ‘reverting’. There are three likely explanations. Firstly, unlike many other plants, the flowers on Hellebores do not drop off, but are persistent on the plant over a very long period. Typically a Hellebore flower may first flower during say July or August but will stay on the plant until at least October or November unless removed earlier. Over this 3-4 month period the colour of the flower will often gradually fade. White flowers will tend to fade to green, pink to a brownish colour. So if you look at your white flowered Hellebores during peak flowering in July or August, they will be white. However by October or November these same flowers will have faded to a greenish colour.
Secondly, if Hellebores are allowed to drop a lot of seed the seedlings may over a period of years effectively swamp and take over from the original plant. This can sometimes give the impression that a Hellebore has changed colour when in fact it is the flowers of a later generation of plants that is being observed. Finally, Hellebores will sometimes flower out of season (for example in late spring or summer) and in such cases the flower colour will not be typical of the true flower colour when the plant flowers normally in Winter.
A precise answer to that question is of course not possible. It all depends on your climate, position in the garden, and the particular season. However in general once they have become established, Hellebores are reasonably drought tolerant. Young plants which have been planted in the last year or so will require some additional watering during dry periods so that they can establish. In particular most young hellebores will require a weekly water over their first Summer in the ground as they will yet to have much root growth. After a few years in the ground Hellebores do develop quite an extensive and deep root system and at that point require a lot less water.
Hellebores will need more water if they are planted in sandier soils, very hot climates or under very large and thirsty trees. In these circumstances, even established plants will probably need some additional watering over Summer. For Helleborus x hybridus under very dry conditions over Summer they can lose all foliage and effectively die back to the underground rhizome, reshooting again in Autumn. However in more congenial conditions such plants are normally evergreen over Summer.
Yes they are. Although it is fair to say that many popular garden plants are also poisonous if you eat them, so there is no need to panic. The toxic compounds in Hellebores make them taste pretty awful, so I have not heard of domestic animals, let alone humans ever eating enough to make them ill.
One of the benefits of this is that animals that are herbivores such as possums, rabbits, kangaroos and deer will leave Hellebore alone as they can detect that they are not good to eat.
Some people can be sensitive to contact with Hellebore foliage, so it is always a good idea to wear gloves and long sleeves if you are planning on doing a bit of pruning or other work with them.