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Wally Richards
Wally Richardshttp://www.gardenews.co.nz
Wally Richards has been a gardening columnist for over 30 years. Check his websites - for gardening news and tips visit www.gardenews.co.nz. For mail order products visit www.0800466464.co.nz. Wally also has a gardening problem help line on 0800 466 464.

Gardening with Wally Richards: The importance of potassium and magnesium – Fruit + Flower Power

Potassium and magnesium news

Potassium is often referred to as Potash because the ash from wood burn contains a good amount of potassium, and magnesium sulphate is often referred to as Epsom Salts. The two are two important elements in gardening.

A long time ago I realised the importance of these two and so I created a product which combined them, in a prill form, 55% potassium and 45% magnesium and called it Wallys Fruit and Flower Power which is one of the many uses of these two elements.

Plants like us, if they do not get sufficient minerals in their diet, they will be adversely affected and do poorly.

Potassium deficiency will show as soft limp plant growth, poor flowering, taste decline in fruit, and general loss of vigor.

I am often asked what is wrong with plants which, don?t seem as good as they could be, even though they are fed well and watered right.

Often the reason is insufficient Potassium.

Then there is fruit, especially citrus which are lacking in juice and flavour.

Tomatoes and cucumbers that don’t have that home grown flavour that one would hope to have.

Plants that have poor flowering or don’t flower at all. Once again the problem can be insufficient Potassium.

Magnesium is involved in chlorophyll production, which converts sunlight into sugars and is involved in activating enzymes.

Because of its role in chlorophyll, the first symptoms of magnesium deficiency show up as yellowing, usually between the veins of the older leaves. In severe deficiencies, the entire leaf will turn yellow or red and then brown, with symptoms progressing up the plant.

There are numerous plants that show this tendency, citrus, Daphne, rhododendrons, tomatoes, passion fruit and roses to name a few.

Once the yellowing starts to appear then already the plant is having problems and even when magnesium is supplied, it takes several weeks before the lovely dark green colour is restored.

During this time the plant is weakened, as the chlorophyll is not working to its full potential which makes the plant more susceptible to diseases and pests.

The amount of energy created from sun light is affected and plant growth is reduced.

During drought conditions, plants suffer and one important aspect to assist in this is Potassium.

It regulates water absorption and retention, influences the uptake of some nutrients and helps to increase disease resistance.

As the weather cools and winter approaches, plants feel the chill like we do, but plants can’t put on a jersey like we can.

The plant’s protection from chills and frosts comes from having adequate Potassium in their diet.

Thus us gardening commentators always suggest to gardeners to supply potash to their plants as winter starts to approach and to avoid using nitrogen fertilisers which only increases sappy growth.

Commercial growers of plants and orchardists use the two elements to ensure their plants have sufficient Potassium and magnesium in their diet.

These two vital elements are blended together in the right balance as required for plants.

For the home gardener we supply Fruit and Flower Power in three pack sizes. 1.25 Kilos, and 2.5 kilos and a bulk bag which is 12.5 kilos making it the best purchase if you have storage room.

The 1.25 kilos comes nicely packaged in a stand up pouch with a 50 gram (50ml) scoop.

It is used at the initial rate of 50 grams (one scoop, just below level full) per square metre around the base of the plant or around the drip line.

Use for any plant that is flowering, fruiting, showing lack of vigor or yellowing in foliage.

Now this next bit might surprise many; but the monthly requirement is 25 grams (half scoop) per square metre.

This should be applied while plants are flowering, fruiting, during dry times and going into winter. Outside of these times a 2-3 monthly dose should be fine.

For fruiting a dose at 50 grams should be applied prior to flowering followed by the 25 grams till harvest. For the likes of tomatoes and cucumbers, apply over fruiting period for best flavour.

I get a lot of complaints that citrus fruit are dry and lack flavour so this will fix the problem.

A number of fertilisers mixes do not contain sufficient potassium, likely because it is a more expensive element which is a pity as it should be at least ample for general gardening use.

Now is a good time to apply Fruit and Flower power around your gardens and repeat each month with a small sprinkling.

It will help to keep your leaves green and the plants will gain more energy from the sun even considering its shorter day lights hours as we head into winter.

It will firm up sappy growth from summer feeding of fertilisers and plant foods.

Also other precautions you should take going into winter include:

  • Protecting your vulnerable plants from frost by using the Spray on Frost Protection; Vaporgard.
  • Mulches used to overcome dry conditions in summer should be removed from under plants to allow the soil to breath and dry out quicker during wet periods. This helps prevent root rots and loss of valuable plants.
  • A spray of Perkfection over plants that could be affected with wet soil is a good help to prevent root damage through wet feet.
  • Spray vegetables and preferred plants with Magic Botanic Liquid (MBL) each week. (It helps them grow healthier and faster).
  • Side dress vegetable plants with a sprinkling of BioPhos.
  • Brassicas (Cabbage etc) that have caterpillars should be sprayed with Wallys Super Neem Tree Oil with Raingard added to prevent the oil washing off with watering or rain.
  • Reduce the amount of water you are giving container plants indoors and tender plants in glasshouses.They do not need so much water now and wet feet intensifies the cold and can be fatal.

Any Questions any time just phone me or email me with your contact phone number.

Image credit: kreus

Products mentioned are from Wallys Range of products and can be found in some garden shops or by Mail Order on www.0800466464.co.nz

Problems ring me at: Phone 0800 466464
Garden Pages and News at www.gardenews.co.nz
Shar Pei pages at www.sharpei.co.nz
Mail Order products at www.0800466464.co.nz

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  1. Thank you Wally I am going to look for Fruit & Flower Power as my cabbages are looking pale! Do you think it could help the silverbeet which is getting rust on the outer leaves?


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