Entries from January 2010 ↓

Dahlias – Time To Come Back Into Fashion

Dahlias are not very fashionable at the moment, although I do not understand why this should be so. They are easy to grow, easy to propogate and give a great splash of colour late in the season when other plants are beginning to look tired.

Dahlias are prolific and long flowering tuberous plants. They have been bred to have a wide range of forms and colours (although there are still no blue coloured flowers).

The groups of dahlia single, anemone, collerette, water-lily, decorative, cactus, semi-cactus and miscellaneous (which includes orchid). Each flower head is referred to horticulturally as a flower although it is in fact a large number of individual flowers.

Single  dahlia flowers  have 8-10 broad petals surrounding an open central disc. It looks like a giant open daisy.

Anemone flowerd dahlias have fiully double flowers each of which have one or more rings of flattened ray petals surrounding a shorter dense group of tubular petals usually longer then the disc petals found in single dahla flowers.

Collerette dahlias have 8-10 broad outer flowers and an inner collar of smaller petals with an open, central disc.

Decorative flowered dahlias are the ones which produce the largest flowers (some as large as dinner plates). They are fully double flowers with broad flat petals which incurve slightly at their margins and usually reflex at the stem. You could compare these to the incurving Christanthemum.

Pompom flowers are fully double flattened to spherical flowers no more than 2ins across. Larger species of pom pom dahlias are sometimes called ball flowered.

Cactus flowers have narrow pointed flowers that can be straight or curved inwards and have recurved edges for more than two thirds of their length.

Semi-cactus flowered dahlias are similar to cactus flower but have broader based petals which are generally recurved towards their tips.

Water lily flowered are exactly what you would expect – they look like water lilies.

When buying dahlia tubers, you are usually given a picture of the flower – its worth keeping this somewhere, so you remember what it looks like.

Buying Tubers is expensive, but they are easy to propogate from cuttings, so you can get many plants from one tuber. I usually put my tuber in a seed tray of compost under cover early in the year (you could keep it on a window sill), then when they have shoots which are 2-3 ins high, I take cuttings, placing them in 3″ pots until they are large enough to plant out when all risk of frosts are over. Each of these plants will form a tuber, so you can end up with a large quantity of plants.

The books all tell you to lift and store tubers in a frost free place when they have finished flowering. However, I have found that usually, they will survive in the garden provided that they do not get to wet. Protecting them with a thick layer of mulch also helps. This is risky, so if you want to be sure that they survive the winter, you should lift them. Be sure that they are dry and free of any mould before storing. Do not plant any tuber which has gone soft – it will not grow.

Most Dahlias have green, broad oval leaves, but some (like Bishop of Llandaff) have bronze leaves which are attractive even when the plant has no flowers.

Most Dahlias are grown from tubers, but recent hybridisation is producing Dahlias which can be grown from seed, although you cannot guarantee what colour they are going to be. Notable among these are  ‘Children of Llandaf’ which have flowers very similar to ‘Bishop of Llandaf’ but the colours range from orange to deep red.

The main pest with Dahlias are blackfly and earwigs. Earwigs do not damage the plants, but they are a nuisance if you are using them for cut flowers, they nest in the flowers and drop off onto you – or your table.

Planting Raspberry Canes.

Today I planted 10 new rapsberry canes. They are 5 Glen Lyon which is an early/late summer variety and 5  Polka, an autumn fruiting variety. I have planted them in a line with 18ins between each plant. This will give room for them to grow and for support where necessary.

The summer fruiting variety will need support and I will put a post in each end of the row. This will be 18ins in the ground and 4 ft high. I will put wire between the posts at 18 ins (the first being 1 ft off the ground) so that as the canes grow, they can be tied to them. The canes will be tied at an angle of 45 degrees, all in one direction. This is so that when next years canes start to grow, they will be tied in  the opposite direction, making it easier to prune after they have finished fruiting.

Autumn fruiting varieties do not need support as they are pruned in early spring and fruit on this years canes.

I already have raspberry canes in the garden – they were there when we moved to the house – however, they are in the wrong place, they are very old and getting a bit weak and the fruits are very small. I tried moving a few canes that year and found the roots to be very long and woody, and they did not take. I will leave the old canes in the garden until the new ones start fruiting at which time I will dig them out and dispose of them.

The new fruit canes may not fruit this year but I look forward to large , tasty raspberries in the future throughout summer and autumn.

Daffoldils

One of my favourite flowers are daffodils. Although I like most narcissi, I prefer the deep yellow daffodils. Unless I want a particular variety, I leave buying bulbs until December or January. The garden centres are then getting desperate to sell them and many really good bargains may be had. You can buy 5 kilo bags for a pound or two. Its O.K. to plant daffodil bulbs up until January, as long as your soil is not frozen. They will flower this year, although they may be a bit late. Then they will continue to flower at the normal time in following years.

When planting Daffodils, particularly for naturalising, you should remember that they are going to be staying there for some time. The method of planting will be slightly different depending upon your soil. If you have light, fertile soil, then all you need to do is make a hole, put your bulb in and cover it up.If your soil isvery heavy and tends  to be waterlogged, then you need to make a larger hole and put drainage in the bottom, either in the form of grit mixed with compost or just plain compost. Similarly if your soil tends to be poor in nutrients, then you should add organic matter first.

The golden rule for planting all bulbs is that they should have twice the depth of soil above them as the size of the bulb. Therefore, for daffodil bulbs which are, say, four inches in depth, then you make a hole which is 12 ins, put your bulb in and cover with 8 ins of soil.

I have planted about 100 daffodil bulbs on a bank in the front of  my garden. Because the soil is so good, I just cut a slit with a spade and put daffodil bulbs in each end. That way, they are close enough to make a good show but have enough room to expand in future years. Be sure that the bottom of the bulb always touches the soil, otherwise it will not grow.You can then leave the bulbs in the ground for up to 10 years or so, until they get too crowded. You know when this is happening because the daffodils will produce leaves but no flowers. That is the time to thin them out. At this point, it is worth digging all of them out and replanting as you wish. Give them extra organic matter if you are re-planting in the same place. You will find you have upwards of ten times as many bulbs as you planted in the first place.

You should always dead head daffodils, that way they do not put there energy into making seeds but will grow their bulbs instead. You can grow daffodils from seed, but it is a very long process (about three years or more). Leave the leaves on the plants for six weeks after they have finished flowering. There is a lot of nourishment in them which will go back into the bulb to help feed it for next years flowers. Do not tie up the leaves as this prevents the goodness going back down.

Roses-The Nations Favourite Flowers

Roses are the nations favourite flowers. This may, in part, be because there are so many different types that there is one to suit every situation.

Species Roses are the original ancesters of all our modern hybrid Roses. They tend to be large, only to flower once a year and have a restricted number of colours and flower types. However, they do not grow suckers. All other roses have been created by growers and are hybrids. They can be grown as bushes or standards and many varieties of climbing and rambling roses are available. Small, ground hugging roses can also be bought. There are known as Patio roses . Standard Roses are simply bush roses which have been grafted onto a small tree to give them a long stem.You can also buy ‘weeping standards’ which are rambler roses grafted onto a long stem. These look much less formal in a mixed border in a small garden than its more formal cousin, the standard rose.

It is sometimes difficult to choose roses, given the wide variety of colours and shapes of the flowers along with the variety of types. However, always consider where you are putting it, how large it will grow amd what it will eventually look like, before coming to a decision.

Unlike many other shrubs, roses should always be planted a little lower than they grew in the nursery , about 1 in (2.5cm)  will do. However, the grafting point should always be below ground. The reason for planting it lower is to encourage growth of new shots below ground. If you are planting in Autumn, they should be pruned back hard immediately after planting. This ensures they do not suffer wind damage during winter and that they put all their energy in establishing a good root system. Always keep all newly planted  roses watered throughout their first year, then ensure their root system does not become too dry.

Suckers are shoots which have grown from the original root below where your hybrid rose has been grafted. If you have suckers, then they should be removed as soon as possible, since they are usually stronger than the hybrid and will take over the plant. Remove by digging down a little towards the root and pull off the sucker. If you cannot pull it off, the cut it off as near to the root as possible.

Pruning on hybrid bush roses is carried out every year in early spring just before the bush rose start to grow. This is so that you can assess the amount of damage caused by frosts and cut it out. The principle of pruning is that the harrder you prune, the more vigorously the shoot will grow. So, get into the habit of cutting back weak shoots further than the strong ones.  Bush standards are pruned just like ordinary hybrids whilst weeping standards are pruned after flowering, just cutting out very old, diseased or overcrowded wood.

Dead-heading Roses (removing dead flower heads)  particularly continuous flowering varieties will ensure a supply of blooms through summer and autumn and often into early winter. Some varieties are grown for their spectacular hips, so of course, you do not dead head these.

Roses have their own particular pests and disease, mainly blackspot, mildew and greenfly.  Mildew shows itself as a mealy, pale grey coating on leaves, bud, flowers and young shoots. This results in yellowing and general lack of vigour. It is worse when the roots are dry. It thrives in cool damp and humid conditions, so ensure your roses are not overcrowded and are not being overwatered. Mulching will also help keep it at bay. Remove and burn any leaves showing signs of the disease and if it is persistant  you could spray with a copper fungacide.

Greenfly are aphids. They suck the sap from your roses causing distortion and particularly attack the young growing tips. Greenfly excrete sticky honeydew on which sooty mould can grow, and transmit virus diseases. There are a number of predators, such as ladybirds and hoverflies, which eat greenfly by the thousand, so the trick is to attract these into your garden. You can grow French Marigolds (Tagetes) close to your Roses to attract these. You can also rub the greenfly off with your fingers (they feel sticky) or you can spray them off with a powerful jet of water. You could also use insectorcidal soap but since the soap only lasts a day, it seems to me to be a treatment which introduces  foreign material into your garden a bit unnecessarily.

Black Spot on roses is a fungus. It starts as a small black spot and merges into large dead areas.which drop out and leaves may wither and die. If your roses become infected with black spot, then ensure that they are not too overcrowded. Remove infected parts of the plant and burn them. Spray the rest of the plant with dispersible sulpher if the infection is really bad. Hard Pruning in autumn will kill off any remaining overwintering spores. Burn all the prunings.

Roses are beautiful flowers to grow and, provided you look after them, are usually free from pests and diseases  and will give years of pleasure. . Every garden deserves at least one.

Perennials, Bi-Annuals and Annuals.

Like most things, gardening has its own language and once you know that language, you can better understand how to garden well. A knowledge of Latin is useful, since many of the plant names have their origins in Latin. Even new varieties are using Latin in their names. However, this is not necessary since you don’t really need to know the meaning of the names to decide whether they are suitable for your garden and whether you like them. Some words, however are peculiar to gardening aand you need to know what they mean. Perennials, Bi=annuals and Annuals are three such words. Bi-Annuals are also often called Biennials.

Perennials are simply plants which will grow year after year. They generally refer to ornamental plants. When it come to flowers, there are perennials which die down to the ground every winter and shoot from the ground again in spring. These are known as ‘herbacious perennials’. You can cut these down as soon as they die back, if you wish. This makes your garden look tidier. Hoever, some seed heads (such as Poppies) look very attractive in winter when the frost settles on them. and some will feed birds. So you need to think about what you want to cut down and what you want to keep. A few years back, the general advice was to cut them all back since they can harbour pests and diseases. This is true. They can harbour pests and diseases and if the plant looks unwell, cut the dead foliage off. However, we now know that not all bugs are harmful so some  hiding places are good for your garden. I generally leave dead foliage for the worst of the winter. It protects young shots from frost and snow, then I cut it back when the worst of the winter is over.

Some of the most useful of the perennials are those which are either green over winter or even flower. I have had Polyanthus flowering all winter, even in the snow. It lifts my heart to see them. Pansies have also been bred to flower during the winter and these also provide colour when we most need it. Some plants naturally flower in the winter, such as Hellebore. You will find that generally, plants which flower in winter have very little or no scent as they are not trying to attract pollinating insects by scent.

Bi-annuals are plants which only flower in their second year and then die. However, some plants which we know as bi-annuals are really short-lived perennials and will flower a second, third and even a fourth time if we treat then right. Antirhinums are one of these plants, as are sweet william. After they have finished flowering, cut them back to three or four inches. They will flower then the following year. The problem is that they will become poorer in flower quality and will also become very woody, eventually  becoming unatractive plants. Some plants such as foxgloves have been bred so that they are true perennials rather than bi-annuals, although the original wild foxglove is, of course, still a bi-annual. Although bi-annuals , traditionally, grow the first year and flower the second, if you sow them early enough, you can persuade them to flower in their first year (and then they die).

Annuals are plants which grow, flower  and die all in one year. This group of plants include some of the most showy of our garden flowers, those plants we call ‘bedding plants’ and plants we call Half-hardy. This means that they will not live through frosts, so we need to sow the seed in a frost free place and wait until the frosts are over before planting them out. Some of the annuals (known as hardy annuals) can be sown where they are going to flower. Indeed, some plants need to be sown where they flower. These include many of the Poppies. This is because they do not like their roots being disturbed.

As you can see, different types of plants need different treatment, so you need to know what type of plants you are dealing with and treat them acordingly. That way you will get the best results from your seeds and plants.

Growing Potatoes in Bags or Bins.

If your garden is small, or even if you have no garden, you can still grow potatoes. In fact if you grow them under cover you can harvest your first potatoes up to a month early (or even at Christmas).

You start off either with a bin (an old dustbin is great) or a large bag (I find the bags compost come in is great- turn them inside out so they are just black and look nice.) If you are using a bin, put crocks in the bottom for drainage. A hole or two wouldn’t go amiss. If you are using bags, make a few holes at the bottom for drainage.

Place 3 -4 ins of soil or compost in the bottom of your container. Spread out you seed potatoes on top of the soil. (5-6 is more then enough in both a dustbin or  compost bag. This will not give you huge potatoes but will give you a decent harvest of medium sized potatoes. Next put 3-4 ins of soil or compost on top of you seed potatoes.

When you see green shoots from your seeds, then cover then with another 6ins of soil or compost. Repeat this process 4 or 5 times or until the bag or bin is three quarters full. Always leave the top of the bag open to the elements.

If you are growing the potatoes under cover, then you will need to water them regularly. Otherwise only water in dry weather.Be careful not to overwater – your potatoes will rot and smell nasty.

Your potatoes will grow normally as though you are growing them in your garden. Just leave them to do their thing. For early potatoes, you harvest when the flowers form and use the potatoes immediately. This will be in June to July for first early potatoes and in July – September for Second Earlies. For Maincrop Potatoes You leave them until after the flowering period is finished. Then harvest. This will be in September to October. Really, though, this method is best used for Early Potatoes.

To Harvest your potatoes, you simply empty your bin or bag. It is as easy as that. You get good potatoes with very little problem from any pests or diseases.

Starting off Potatoes by Chitting.

I laid out my seed potatoes to ‘chit’ Today. I am going to grow Pentland Javelin, a first early potato which is eelworm and scab resistant and Romano, a maincrop Potato. I have laid them seperately in egg  boxes so that they sprout in a light, cool place. I will plant them in March when most of the frosts are over.

There is a good guide on growing Potatoes at the BBC Gardening Guide

How to grow potatoes in your garden

Potatoes take a little bit of work to grow in your garden but are worth it for the taste. If you have a small garden, then it is hardly worth growing maincrop varieties since they are so cheap to buy and they do take up a lot of room. There are really only four processes which you need to go through to grow potatoes successfully and once you know these, it becomes easy.

There are a large number of varieties of potatoes, each one performing different functions. If you use most of your potatoes for boiling, then you may want a different variety than if you use them mainly for chips. Some varieties perform a number of functions. So before buying seed potatoes, look caregfully at what they are best for. In addition to their uses, some seed potatoes are better at repelling pests and diseases than others. If you are growing potatoes for the first time, you will not know what pests and diseases are in your garden (if any) so err on the safe side. Although you can grow potatoes by planting any potato in your garden. It is always better to use seed potatoes because these have been specially treated and are guaranteed to be free from disease.

Apart from the various varieties, there are also also diferent types of potatoes which indicate when they are planted – and harvested. The packs will indicate this very clearly. Early varieties are dug and eaten straight away whilst Maincrop varieties are harvested in autumn and can be stored for winter use.. Early varieties are also divided into first early and second early types. Further indicating the time for planting.

The first thing you need to do after buying your seed opotatoes is to ‘chit’ them. This means you lay them  out in a frost free place to sprout. Eggs boxes are adeal for this. However, you can use any container for this (I often use seed trays if I don’t have egg boxes available. You only want a few sprouts on each potato so if you have more than two, rub the smaller ones out. This avoids to much competition and a large number of smaller, inferior tubers. The sprouts should be green and strong. Keep the potatoes in a cool, light place. Never put them in the airing cupboard or other warm dark places. The sprouts will become light coloured and long and weak.

Once you have your sprouted potatoes, it is time to plant them. Potatoes like water-retentive soil with planty of organic matter for best results. If you do not have enough well rotted compost or manure for your whole plot, then dig the planting furrows deep and put a layer of compost in the bottom. Do not lime your potatoe plot as potatoes prefer an acid soil.

Planting time for potatoes depends upon where you live and the method you are using. The earliest crops can be grown under black polythene in late winter. This is an ideal deep bed method. Plant the early varieties in early to mid spring. You plant these in rows 2 ft apart with the tubers 12 ins aprt and about 6 ins deep.  Maincrop potatoes are planted at the same time but the rows are spaced 2ft 6ins apart and the tubers are 15ins apart.

If the shoots appear before the frosts are over, cover them with soil to protect them from frosts. When the shoots are 6- 8ins tall spread a handful of blood, fish and bonemeal along each row and earth up by putting the earth between the rows over the shots, leaving a fraction of an inch showing. You can repeat this process once of twice more. This is very god for controlling weeds and it also ensures the tubers do not push up into the light. If tubers do push up, then cover them with soil. If tubers see light they turn green and become poisonous.

Early potatoes are harvested when they flower. Take only what you need immediately, leaving the rest to grow on. Maincrop varieities are harvested in mid autumn. Cut the foliage back and put it on the compost. However, if there is any sign od disease in the foliage, burn it.

Potatoes are afected by eelworms, wireworms, potato blight, scab and a number of other diseases. These are all either avoidable by buying the right tubers or are curable.

How to make Compost

Ideally, really good compost is supposedly brown and crumbly with the sweetest of smells, like woods in the autumn. In fact, it very rarely is. If you have a very big compost heap with only the very best organic material to build it with, then you can achieve this in spring and summer. Most of us, however build our compost heaps with whatever organic material available and the compost is very variable with a lot of semi-rotted fibrous matterial. That doesn’t matter. It will still improve the soil and will certainly do no harm, it will just take longer for it to become  “humus”.

Getting good quality compost takes care. Each material needs different treatment. There are some materials which are especially useful.Straw is one of them, whilst others, such as grass clippings need to be mixed with other materials to achieve good results. If you make a heap of grass cuttings alone, it will just become slimy and smelly. Mix grass with larger weeds, shredded paper or straw. However, straw and paper is very dry and should be soaked in water before adding to the compost heap. Never use glossy paper in compost – it does not rot well and contains too much lead. Always shred paper, never put wads of it in your compost heap – it takes too long to rot.

There are some things you should be careful of putting on your heap. Some root systems will survive being put onto the compost heap and will grow again once spread over your garden. Never put roots from bindweed, stinging nettles or dandelions on your heap. Burn them, then you can either add the ash to your compost heap or spread it on your garden.

The ideal compost is made thus: start off with a 6 in layer of course material such as horse manure, straw or large weeds. This will give you a free flow of air. Then add materials such as grass cuttings, leaves and weeds from the garden until you have another 6 ins. Sprinkle some compost activator or nitrogen fertilizer 0ver this layer or add horse manure at this point (the nitrogen in it will act as a compost activator). Next add another 6 in layer of garden materal. Add a dusting of lime. Next add leaves and grass cuttings, then lime. When you have finished building your compost heap, cover it with carpet. This will keep the heat in and keep it dry. The compost heap will rot down and shrink in the first week, so you can add an extra layer at this time should you want to. The amount of compost you can make depends upon the amount of material you have, the way you build your heap and the weather. In a hot year, you should get two good binfuls in the summer, one in the autumn and if you are lucky, one in the spring.

Soil – And How To Treat It

The soil in your garden is the basic raw material upon which all plants depend. It should never be dismissed as merely a collection of mineral particles used to anchor the roots of your plants or, worse still as “dirt”.

The main constituent of  soil consists of rock partocles broken down by erosion to produce the different types of soil. However much of  its make up is organic matter, animal and vegetable remains in  various stages of decomposition along with air and water. This really is all you need to support  plant and animal life.The ideal soil has a crumbly structure full of organic matter. It drains well enough to prevent it becoming waterlogged in heavy rain and is capable of providing the nutrients needed by plants to grow healthily.

There are five main soil types: peat, chalk, silt, sand and clay. Generally, the rock upon which your soil is sitting dictates what kind of soil your have. Of course, there are many variation on the themes – such as sandy loam. This means that whilst a high proportion of your soil is sand, a large proportion is also silt.

When seen together the five different types of soil look very different. Most of us do not have purely one type of soil. However, here are a few pointers to soil types and how to improve them.

Clay is a heavy cold soil which feels sticky when moist and hard and compacted when dry. Because it is made up minute particles, it drains very poorly. However with some work, over time, it can be turned into a very workable, fertile soil. First, dig clay soils in the autumn when it is moist but not too wet. When digging in autumn, leave the top rough and uneven to expose the maximum area to the elements over winter so that freezing and thawing will work their magic. When digging incorporate plenty of organic matter to improve fertility. In addition, if your soil is very heavy, add course grit into the mix, this will help drainage. Raising the area of soil in which you  are goung to grow will help drainage.

Sand is a very light soil which tends to drain easily. It can therefore be cultivated when other soils are still water logged. However, because it drains so easily, nutrients are washed away so you need to add organic matter and fertilizer to the soil to improve fertility.

Silt soil has the same sort of  drainage problems as clay soil and the way you treat it is very similar, although you should not need the grit. However, adding plenty of well rotted compost and manure will help no end.

Chalk soil has two big disadvantages. Firstly, it tends to be very thin, dry and hungry. You need to add plant nutrients in the form of organic matter and fertilizers. Like sand, chalk soil drains very easily and the nutrients drain away with the water. The second disadvantage is that it is very alkaline and so unsuitable to many plants. However there are plants which require alkaline soils, so if you do have chalky soil, work with it and look carefully at plant requirements before trying to grow them.  Chalk soils  need to be covered  as much as possible, so use green manure crops during times when you are not growing other crops and mulch between plants where ever possible.

Peat is the easiest type of soil to grow plants in. If you are lucky enough to have it, you will know that it is very fertile. You can grow plants intensely. However, peat soils do tend to be acid and will therefore need generous applications of lime to keep the balance. It also tends to dry out in summer and if allowed to dry completely  it will shrink and be difficult to wet again.  The nature of peat soils mean that they are high in organic matter but probably low in nutrients so although it is not necessary to add organic matter , fertilizers may be needed.