Small White ‘Pieris rapae’ Butterfly and caterpillar. Vegetable pest identification

Small White Pieris rapae are considered a garden pest as they eat cabbage and tomatoes.

Small White butterfly laying eggs on underside of a cabbage leaf

Small White ‘Pieris rapae’ caterpillars young and old

The caterpillars will eat your brassica as well as your tomato plants.

They are very well camourglaged and difficult to see.

They mainly come out under the safely of darkness to feed.

The caterpillars eat the leaves as well as the unripe tomatoes.

Tomatoes eaten by caterpillars

Photography Neil Bromhall. www.rightplants4me.co.uk

Are you on Acid

ACID LOVING PLANTS AND LIME INTOLERANCE.

Acid loving plants could just as easily and probably more accurately be called lime hating plants. It is the presence of lime or calcium in the soil that causes all the problems.

There is quite a range of popular plants that need acidic soil conditions to thrive. These include plants such as Rhododendron, Pieris, Erica, Pernettya, Kalmia  and Pachysandra. They are often termed Ericaceous plants suggesting they all belong to the family Ericaceae (but there are many others).

Compost for lime hating plants is often called Ericaceous compost.

Plants whose natural habitat is alkaline often grow perfectly well in acid conditions but the converse is not often true.

Soil is classified as being alkaline or acidic by its pH value, for example pH 8. (This term comes from the French word ‘puissance’, meaning power or strength and gives us the ‘p’. The H is for hydrogen. And the number refers to the concentration of Hydrogen ions in the soil.) Below pH 7 is considered acidic and above is considered alkaline. Your soil pH can be tested with a kit using solutions mixed in small tubes where it is judged by the colour it turns or, more conveniently, there are inexpensive electronic probes available.

These you simply push into the soil and take a reading.

A much cruder test but ideal for a quick assessment is to see what is growing either in your own or neighbouring gardens. If there are any of the plants mentioned above then the soil is going to be acid.

A word of warning here. Soil conditions can change over a surprisingly short distance so this method is only a guide.

Symptoms of lime intolerance are often called chlorosis.

Plants need to get energy from the sun. To do this they produce a green pigment called Chlorophyll. This is what makes leaves green. To produce this pigment the plant constructs the chlorophyll molecule based on iron before replacing the iron with nitrogen. So iron and nitrogen are important. Undernourished plants often have pale green or yellow leaves because they do not have enough nitrogen. Give them a feed that contains nitrogen and they will soon green up and look healthy once again-easily cured.

However, too much lime in the soil prevents acid loving plants taking up iron. Without iron there is no green chlorophyll production and the plant looks pale, typically showing yellowing between the leaf veins. No matter how much nitrogen you feed to plants under these conditions they will not green up. 

The Cure.

The obvious way to avoid problems of chlorosis is not to grow acid loving plants on alkaline soil. Knowing this, in regions of alkaline soil, many of us choose to grow our Rhodo’s or Pieris in a pot. This is fine as long as you remember to use ericaceous compost and to be aware that if you are continually using hard or limey tap water to irrigate your plants you will gradually build up the levels of calcium in the compost so raising the pH and making life uncomfortable for your plant. It will eventually show signs of chlorosis. Watering with soft or rain water ( I use water from my dehumidifier for my one and only lime hating plant.) prevents this problem.

In the open garden the soil can be acidified by adding sulphur which in combination with water becomes sulphuric acid. Because there is usually such a great reserve of calcium in alkaline soils this is a fairly temporary measure and if you choose this method you will have to repeat the dose  at regular intervals depending on the level of alkalinity.

An alternative is to use chelated iron compounds of which Sequestrene is a well known brand. This provides the iron in a form that can be taken up by the plant. Again this will need to be applied at regular intervals.

SIDELINES

Confused by the terminology?  Alkaline, limey, calcium rich and high pH all mean the same thing and that is that you have lime in your soil and you cannot grow rhododendrons.

High pH can have its advantages. If you are a veg grower then a high pH controls the incidence of club root on Brassicas.

If you live in an area with alkaline soil but are desperate to grow acid loving plants then the best long term solution is to create raised beds that can be filled with an acidic peat enriched soil.

Hydrangeas will grow quite happily in alkaline soils but you will not get blue flowers. In limey soils the aluminium that the Hydrangea needs to produce blue flowers is locked up so the flowers turn out pink. Hydrangea colorants contain aluminium that is available to the plant regardless of soil conditions so turning the flowers blue.

Colorants are available from garden centres.

This articles is just one of the articles found on the interactive plant finder, planting advice and pruning guide CD-ROM The CD-ROM contains 3,500 UK garden plants with 9,000 photographs plus illustrated pruning tips

Cucumber. How to identifying male and female flowers.

Cucumber flowers

Behind the bright yellow female flower is a miniature cucumber.

Female cucumber flower

For indoor varieties you do want to pick off the male flowers otherwise your developing cucumber to be pollinated by the male flower and the cucumber will taste bitter and not very pleasant.

 

 

Outdoor varieties known as Cucirbit need both male and female flowers to produce fruit, so don’t pick off the male flowers.

Male cucumber

The male flower is also bright yellow and grows close to the stem and only has a thin stalk. For indoor varieties the male flowers should be removed as soon as possible to avoid the possibility of fertilising the female flower on the developing cucumber fruit.

Male cucumber flower

Cucumber pollination by bumblebee

The Bumblebee visits a male cucirbit cucumber flower to collect pollen.

Bumblebee pollinating a female cucumber flower

When the bee then enters the female flower, some of the pollen is transfered to the stigma which fertilizes the flower.

The cucumber fruits will swell and hang down as it grows, so provide support and enough space for the cucumbers to grow.

Cucumber growing

To grow.

 

 

 

Sow the seeds in February or early March. Plant the see edgeways in 1cm deep in seed compost.

Plant on in John Innes compost No 3 in large pots or growbags

Cucumbers like moister conditions compared to Tomatoes

Planting to harvesting takes about 12 weeks

Indoor vatieties:- F1 Hana, Burpless Tasty Green, Crystal Apple. Luxury, Masterpiece, Zeina

Cucurbit Outdoor varieties:- Crystal Lemon, Bedfordshire Prize, King of the ridge, Puree Hybrid, Zeppelin, Patio Pik, Long white Paris, Japanese varieties, Kyoto, Tokyo slicer

Photography Neil Bromhall.  www.complete-gardens.co.uk

Courgette how to identify male and female flowers

Male and female courgette flowers

 

 

 

The female has a miniature courgette fruit at its base of the flower whereas the male doesn’t.

The flowers have been cut to expose the male pollen and female stigma.

 In rainy weather, the courgettes can fail to form due to a lack of insects needed to pollinate the female flower.

You can dab the pollen from the male flower on to the stigma of the female flower. The flowers have been cut open to expose the male pollen and the female stigma. The female flower will need to be open to be pollinated. This photograph is of an immature female flower which has not opened yet.

Photography Neil Bromhall www.complete-gardens.co.uk

Tomato blight on leaf

The leaf shows the early signs of tomato blight.

Cut the infected leaves off and destroy.

Give your plants a uniform supply of water.

Do not over water then leave the plant dry for any period.