Over watering plants is a waste of time and money

Over watering plants is a waste of time and money

Plants have different water requirements which vary with their stage of growth.

Factors affecting water requirements:

• Size of plant • Speed of plant growth
• Stage in life cycle • Weather conditions
• Type of root system • Position in garden
• Size of leaves • Type of soil

Plants obtain the water they need from the growing medium, through their root systems or from the air. Many specialised plants such as those growing in tropical conditions have aerial roots or specialised leaves which absorb water from the surrounding air, storing it for use at a later date.

When plants are grown commercially or in amenity situations they often require more water than can be supplied by natural means. In such situations water has to be supplied by artificially to ensure good quality plants.

Before watering it is important to assess whether a plant requires irrigation to avoid wasting water and flushing plant pots of nutrients. Indicators include wilting, light coloured compost, a gap between the compost and the pot where the compost has shrunk as it has dried, and the pot being lightweight.

Water to the point of run off and stop, allow water to soak in and re-water if necessary. Large plants need enough water to allow soil to become wet to a depth of 15cm. A thorough soaking which percolates deep into the soil will encourage plant roots to grow deeper making them more drought tolerant. Irrigating little and often does more harm than good.

Equipment for watering plants
The type of equipment used for watering plants will depend on the number of plants requiring watering, the regularity of watering and cost of equipment.

Dipping plants
Used for watering individual dry container plants. Dip pot completely and leave until bubbles stop rising, remove and leave to drain.

Watering cans
Used for watering individual plants in the soil or container plants such as seed trays and pot plants. When watering plants in the soil the rose may be removed, however, you should make sure soil is not washed away from the root system.

Use a rose when watering seedlings, turning holes upwards for a gentler sprinkle. Stop once run off occurs and wait until water soaks in before continuing.

Hoses come in a wide range of sizes from 1.4 cm – 2.5 cm bores, with most nurseries using 2 cm hosepipes. They may be made of rubber or plastic, the most robust have a nylon braiding. Lay flat hoses are frequently used to irrigate growing areas. Hoses are used widely in amenity and commercial situations for watering plants; they can be used with sprinklers, roses or spray lances. Hoses can be permanently attached to taps using jubilee clips or be removable by using geyco or screw couplings.

To avoid scorching foliage never use sprinklers in hot sun

To avoid scorching foliage never use sprinklers in hot sun

Used to water large areas such as lawns. May be static, having to be moved periodically to a new area, or rotating when the head moves round, or from side to side. These cover wide areas but may still need to be moved if large areas are to be watered. The disadvantages of sprinkler systems are evaporation and overlapping spray patterns, leading to over watering within the overlapped areas.

Seep hose/porous pipe
Used for watering borders, beds, and within nursery areas for watering container plants. Seep hoses consist of a polythene tube with a sewn seam along its length, which allows water to slowly trickle out. This system is liable to blocking by calcium deposits, but causes less damage to soil media than many other systems.

Porous pipe is made from recycled rubber and allows water to slowly drip out onto the bed or border.

Both of these systems deliver water at soil level which avoids excessive evaporation. They may be covered with mulch or left on the top of the soil.

Oscillating spray lines
Consists of long metal or plastic pipes that clip to each other with a series of holes along their length. Usually mounted on stands, water pressure causes them to rotate back and forth. As with sprinklers, it is important to plan out carefully the position of spray lines in relation to each other, and therefore avoid overlapping spray patterns.

The following points should be observed to avoid damage to plants and soil, and accidents to members of the public.

• Never use sprinklers in hot sun, to avoid scorching foliage
• Do not over water plants – it wastes time and money and can cause disease problems
• Do not underwater – it causes checks in growth and poor quality plants
• Do not use watering cans that have contained chemicals
• Never water near electrical equipment, remember electricity kills
• Avoid leaving hoses and other irrigation equipment laying across walkways
• Outside taps should have an anti flowback device (to avoid contamination of water supply)

Good luck and happy gardening!

For any gardening tips why not contact Tom Cole, Senior Horticultural Lecturer, Writtle College, Chelmsford, CM1 3RR by post (including a SAE) or by email at tom.cole@writtle.ac.uk

fruit against fence1 We’re just at the tail end of the pruning season for apples, pears and soft fruit such as raspberries and gooseberries.  For stone fruits such as cherries and plums there’s still time as these aren’t really pruned until they are well and truly showing growth, usually July/ August to avoid bacterial canker and silver leaf.

Key to pruning apples and pears for the garden is to always remove dead, diseased and damaged growth, any suckers from the rootstock, reducing crossing branches by cutting back to outward facing buds and light shaping of the overall canopy.

For summer fruiting raspberries cut out last years growth and tie in vigorous canes into a support system leaving around 10-15cm between each cane.  Take out weak growth.  The tops can be bent over the top wire and tied to it.  Make sure ALL canes are securely attached to supports to avoid any damage during the season.  I’d then remove any growth creeping into paths; these can be used to plug any gaps in the row.  Feed with a high potash feed; personally I use Top Rose at a rate of 50-100g/m2.  Lastly, apply a healthy layer of well rotted organic matter to a depth of 10cm.  Autumn varieties can be cut hard to the ground as they flower and fruit on present seasons growth.

For blackberries and other hybrids treat in a similar way to summer fruiting raspberries by removing last years growth and then tying in the shoot growth to a support system by weaving the growth between the top wire and middle wires. Tie in to secure stems.

With blackcurrants minimal pruning is required. You’re looking at developing a goblet shaped plant. Only remove central older stems if supported by new growth at its base. Any growth growing towards neighbouring plants is cut back to the ground or to where there is an outward facing bud.

bare rootWith gooseberries, red and white currants treat them together. These all produce flowers and fruit on spurs. Again you are looking at developing a goblet shaped plant. Work logically round the plant by taking each branch leader, pruning hard any side/ lateral growths to 1-2 buds and tipping leader. With gooseberries try to maintain a clear ‘leg’ to enable good air flow and reduce powdery mildew. The leg is an area of clear stem between soil level and where the canopy of the plant begins; its roughly 15cm in length.

Why not try blueberries this year in pots if you haven’t got acid soil. If buying plants for the first time plant them in pots at least 75 x 75cm and do not prune for at least 2-3 years as this will enable the plant to produce a great framework to support flowers and fruit.  Feed during the growing season with liquid feeds high in potash. If yellow young leaves develop drench plant with any products containing sequestrene (contains iron) and mulch the top of the pot with ericaceous compost.

Good luck and happy gardening!

If you have any garden questions email me at tom.cole@writtle.ac.uk. Alternatively, post your questions to Tom Cole, Senior Horticultural Lecturer, Writtle College, Lordship Road, Writtle, Chelmsford, Essex, CM1 3RR.

Daffodil Cheerfulness

Daffodil are already in bloom in many gardens

We’ve seen usually high temperatures over recent months, but we mustn’t forget that very often February can be the coldest month of the year. The milder spells has encouraged the growth of plants and bulbs, with Daffodils, a flower you would normally associate with spring seen in bloom.

If you have Cyclamen Coum their bright pink blooms will also be creating a warm glow in those sheltered areas of the garden. Remember Cyclamen like well-drained soil, so they are sometimes better grown beneath trees where they will self-seed. These can also be bought from garden centres growing in pots, as can many other bulbs if you’re containers and planters were not planted up in autumn. Tulips, Narcissi, Scilla and Hyacinths when planted up in your containers can suddenly make you become the envy of your neighbours.

We can all be impatient sometimes but we shouldn’t put plants out in the garden yet that aren’t fully hardy. Always have some horticultural fleece on hand to cover some of those softer plants that you might have planted in the garden last year.

Whilst talking about this coming season it’s a great time to get out to your local garden centre or shop to plan what annuals you might be sowing in your garden this summer. Remember many annuals can be direct sown to create masses of colour through the summer. If you have the use of a conservatory or greenhouse then you could think of growing some more annuals under glass, nurturing them until after Easter when we can plant them out in the garden.

If you’re feeling brave enough venture out yourself to do some real gardening, instead of sitting indoors reading seed catalogues. Most gardeners, however, will be spending their time looking forward to warmer weather with indoor seed sowing in mind perhaps on the kitchen or bedroom windowsills.

Watch and wait till the days start to get longer and light levels start to increase. Some seeds are hardy and will germinate quickly and make seedling plants in just a few weeks – others are tender and take many weeks to grow to flowering and can’t be planted out until frosts are finished in May.

These slow, tender ones, often called Half-Hardy Annuals (HHA) are the seeds that need the space and warmth of indoor cultivation. Among them are bedding geraniums, regal pelargoniums, bedding begonias (B. semperflorens), salvia and verbena.

For maximum germination of small and relatively expensive seeds, sow them in good Seed & Cutting Compost. Follow the instructions on each packet and place the tray in a propagator or warm place to maintain an optimum temperature of 70-75F (21-24C). Provide a steady soil temperature both day and night for best results

If the weather stays mild regular mowing of the lawn is essential even at this time of the year. However, never cut your grass if it is wet or frozen as this will damage it. Set the blades high when mowing which nips the grass back and helps it to grow tightly and produce stronger growth. Always remember to brush away any wormcasts with a besum broom or a yard broom prior to mowing, if not it can result in a muddy mess.

For me it is too early to prune established bush roses, I like to do it at the beginning of March. Importantly though, gather up all fallen leaves and any other foliage that show the dark brown patches of rose blackspot disease. By removing foliage that was infected last year you will reduce the carry over of the disease to next season’s growth.

If your roses suffered from blackspot disease last year, remember to start spraying your rose bushes when buds burst in March, so that they have a clean start to the season. Also give them a good feed of a balanced fertilizer to get them going.

Galanthus nivalis

Snowdrops are already starting to bloom

Continue to plant hardy trees, shrubs, climbers, roses and hedges on fine days, as long as the soil isn’t frozen solid or waterlogged. At this time of year you may be able to get your hands on bare-root plants or root balled. These are cheaper than containerised plants, so a better bet when you have a lot of planting to do – such as a new rose bed or hedge or maybe some tree planting.

Last but not least, I can’t finish without mentioning my favourite early bulb: Snowdrops. These are already starting blooming. Remember to divide any overcrowded clumps immediately after flowering has finished as the bulbs move much better when the plant is in leaf, also called ‘in the green’.

Most importantly enjoy your garden.


Magnolia campbellii

Magnolia campbellii

The Magnolia sprengeri var. diva is coming into flower, two months early at Borde Hall Garden near Haywards Heath, West Sussex, but with hard frost forecast could this damage the flowers?

We shouldn’t worry too much – after all there is nothing we can do to stop Mother Nature’s quirky turns – and instead of searching on Amazon for arboreal-sized duvets, perhaps we should look forward to what we can expect to see during the ‘normal’ spring magnolia flowering period of March and April.

Borde Hill has a fine collection of Magnolias, many planted in the 1920’s by the gardens founder, Col. Stephenson R Clarke, a mad keen plant collector and a committed magnoliaphile.  Seven are classified as ‘champions’ and two as ‘remarkable’ (champion near miss) by the tree measuring folk. Magnolia campbelli at 19m tall is always an impressive sight – a bright pink beacon in the Sussex countryside indicating to planes in the Gatwick stack that you are over Borde Hill. Another ‘wow’ is Magnolia sargentiana var.robusta.  First flowering in 1938 with five fine blooms (we are told) and again in 1940 with over 100 blooms, nowadays the bloom count must be in four figures.

Whilst having plants in the size ‘premier league’  is important, we, as all good tree folk should, think to the future . In  Col. Clarkes day, magnolia varieties were quite limited. Today there are 100’s to choose from – pinks, whites, purples and even yellow – yes, yellow.  In the past few years we have planted over 75 new varieties including Banana Split, Joli Pompom and Star Wars (whacky names is not usually the main criteria when choosing  new plants).

So as Jack Frost hops around your garden tonight  turning your impetuous blooms brown, rest assured that most magnolia flowers are still tightly tucked up in their furry perules (botanical overcoats) waiting for the warmth of spring to reveal themselves.

For more information visit http://www.bordehill.co.uk/

Borde Hill Garden, near Haywards Heath, West Sussex is open to the public daily between 10am-5pm weekdays and until 6pm weekends from 19th March-2nd October and 22nd-30th October.

Entry is £8.20 for adults, £7.80 concessions and £5.50 per child.  A family ticket (2+2) is £23.

Planted container

Inject some colour and scent into the garden by updating your containers

It’s time again to revamp any container that has escaped you over the last few months.  Is it looking tied and sad?  Tom Cole, Head of Faculty for Land & Environment at Writtle College has decided to grab the bull by the horns and step into action and give his containers a much needed makeover.

This gives me a great opportunity to even change the container and opt for a complete change and this in turn has enabled me to putting something new in.

The one pot I’ve got to look at is a lone container residing in a dustbin corner.  Yep… where our bins live for most weeks!  Well I thought I’d jazz up the planting and bring in a few scented smellies and keep to a theme of evergreen foliage with some flowers for a bonus.

The previous pot was an old fibreglass vision around 1.5m high and had a glorious old ivy and a few crocus… slightly sad looking if I had to add anything else.  Out with this and in with a lovely new terracotta urn of around the same height and spread.  The area is light early in the day and a little shady during winter months at the end of an alley between two houses.

As a key plant I had to go with Sarcococca confusa (Sweet or Christmas Box).  This is one of the my most favourite plants for producing a vanilla-like scent which can be quite heady during the winter months.  At Writtle College we have these doted around the campus and they are just lovely.  The leaves are glossy and deeply green.  It is a great compact, thicket-forming shrub that will get to around 2m high if you let it!  A bonus is that towards the end of Winter you’ll get spherical, black or blue-black berries.

For a change in texture I love to use ferns, so what better than to use Dryopteris erythrosora (Japanese shield fern). This is a semi-evergreen producing fronds up to 75cm.  It is a clumped plant where the foliage often turns coppery-pink when young going to green.  In the same tub I’ve added another called Asplenium scolopendrium ‘Angustifolia’ (Harts Tongue) as this one has long, narrow crimped edged fronds.

HeucherellaTo break up the green I’ve added brightly coloured foliage in the form of Heucherella (a cross between two distinct plants, Heuchera  and Tiarella, and shows similarities to both parents).  Although there are many forms; check out this link: http://www.heucheraholics.co.uk/heucherella-shop.html), I’ve used Heucherella ‘Sweet Tea’ with deeply-lobed leaves that change with the seasons. In the spring leaves are amber-orange with a cinnamon-brown star pattern in the centre while in summer, russet, copper and cinnamon tones dominate.

Added to the melting pot try out Helleborus niger (Christmas rose) with lovely leathery foliage and perfect white flowers from winter through to spring.

Lastly, don’t forget to use bulbs or corms to give a burst of colour early in the New Year.  Check out the overall height and try and keep within the scale of the container. Try crocus, snowdrops, winter aconites and or dwarf daffodils (especially ‘Minnow for small bright yellow trumpeted blooms).

All the plants used will be perfectly fine in this sized pot for at least a couple of years…don’t forget though that water does need to escape through winter.  Either pop container on little ‘feet’ or stand on gravel; this will save your pot if terracotta and protect your plants from overly standing in water for too log leading to rots.

Good luck and happy gardening!

For any gardening tips why not contact Tom Cole, Senior Horticultural Lecturer, Writtle College, Chelmsford, CM1 3RR by post (including a SAE) or by email at tom.cole@writtle.ac.uk