Rhododendrons: planting and feeding

Posted by Giedra, 6 May, 3:36 pm

The best time to plant rhododendrons is either in spring, from early April to mid-May, as soon as soil warms up, or in autumn, from early September to early October, so that plants would still have time to root the ground freezes over. Rhododendrons can be planted any other time, if need be, except when in flower or when new shoots are growing fast, which is usually after, and sometimes during, the flowering period. Potted rhododendrons can be planted any time during growing season. Even mature rhododendron bushes tolerate replanting well. Their roots suffer hardly any damage, being compact and shallow-rooted, which is rather an exceptional quality, comparing to other plants. Before moving rhododendrons, water them well, which will make replanting easier, and the plants will not be subjected to the moisture shortage.

Having replanted the bushes, water them thoroughly. If the rhododendron has set many flower buds, it is best to remove some of them, so that the plant would not waste valuable nutrients on flowering before it gets established.

Large flowers of rhododendrons come in abundance, so a generous supply of nutrients is important to keep up their vigour. Both organic and mineral fertilisers can be used on young and adult plants alike. Ideally, a well-balanced fertilizer should contain main elements N:P:K in ratio of 3:1:2. Nitrogen (N) is essential in spring and early summer, when plants are growing fast. Phosphorus (P) is required for flowering and for the flower bud setting. Potash (K) is necessary throughout the growing season, since it aids absorption of other nutrients. Phosphorus and potassium also play a major role in reproduction of plants and seed setting. Due to these elements, shoots grow faster and harden off in due time to withstand the winter freeze.

The best organic fertilizer is well-rotted manure. In addition to feeding plants, it improves soil structure, making it crumbly and well-drained. Mulching plants will also help to replenish the soil with organic matter.

Mineral fertilisers are mostly synthetic. They provide rhododendrons with macro- and microelements. Plants require considerable quantities of macroelements (nitrogen, phosphorus, potassium, magnesium) and only traces of microlemements (boron, copper, iron, manganese, molybdenum and zinc), but the latter ones are very important. The well-balanced complete fertiliser containing all required microelements is ideal for the purpose. Rhododendrons,

grown on acid soil, absorb minerals much better. Larger quantities of microlements could poison plants grown on alkaline soil. Acid fertilisers – nitrogen sulfate, superphosphate, potassium sulphate, magnesium sulphate – are preferable, and, of course, complete fertilisers balanced especially for rhododendrons, both in liquid and granular forms. Granular fertilisers generally are slow-release type, and are used once during the growing season. Liquid feeding can be applied regularly, every 10-14 days. Mineral fertilisers, containing chlorine, are best avoided, since they prevent absorption of the other nutrients. The vigour of the plants, the abundance of blooms, the colour and the size of the leaves are the tell-tale signs whether the plants are getting sufficient nutrients. But bear in mind, that too much of fertilizers is just as bad as too little of them.

The best time to apply slow-release fertiliser is in early spring (March-April), while liquid feeding should stop in mid- to late July. If you continue to fertilise plants later than this, especially in damp and warm weather, rhododendrons will respond with a new flush of growth, which will not have sufficient time to harden off before onset of winter, and will suffer winter damage.

© Mygarden.lt, 2009

 

3 responses to “Rhododendrons: planting and feeding”

  1. It’s impressive that yoou are getting ideas from
    this paragraph as well as from our argument made
    at this time.

  2. Hi there friends, its great paragraph regarding tutoringand
    fully defined, keep it up all the time.

  3. Aw, this waas a very good post. Taking a few minutes aand actual
    effoort to generate a great article… but what
    can I say… I put things off a llot and don’t seem to
    gget nearly anything done.

Leave a reply

Threads instead of leaves (1)

Autorius Giedra, 2012 05 16 16:12

A knee-high birch (0)

Autorius Giedra, 2012 04 10 09:16

Fragrant tots (0)

Autorius Giedra, 2012 03 13 16:18

The smallest of the small – `Silverstone` (0)

Autorius Giedra, 2012 02 02 15:24

`Canadice` – the pick of the bunch (0)

Autorius Giedra, 2011 12 20 15:25

Pineapple guava – the taste sensation (0)

Autorius Giedra, 2011 11 03 10:41

Overwintering lewisias under pots (7)

Autorius Giedra, 2011 10 03 21:11

Plants for the white garden (6)

Autorius Giedra, 2011 09 14 10:50

The white garden (0)

Autorius Giedra, 2011 08 13 21:26

Propagating japanese spiraeas (0)

Autorius Giedra, 2011 06 05 19:05

Cleaning the pond (1)

Autorius Giedra, 2011 05 21 15:32

My favourite kind of plant (0)

Autorius Giedra, 2011 05 17 16:14

Pine candling (3)

Autorius Giedra, 2011 05 04 14:59

How to rake the lawn (12)

Autorius Giedra, 2011 04 08 15:25

Rhododendrons: sun or shade? (6)

Autorius Giedra, 2011 03 05 20:28

Chocolate trees (0)

Autorius Giedra, 2010 12 29 18:08

In the shade of the coconut palm (0)

Autorius Giedra, 2010 11 07 15:35

Pomegranate on the windowsill (1)

Autorius Giedra, 2010 10 13 22:41

Heathers extend the season into autumn (1)

Autorius Giedra, 2010 09 10 09:56

Moving cacti to a rock garden (1)

Autorius Giedra, 2010 08 02 16:21

Wax begonias – modest and beautiful (2)

Autorius Giedra, 2010 07 08 22:24

Lawn daisies (0)

Autorius Giedra, 2010 06 02 12:42

My puffy bears (4)

Autorius Giedra, 2010 05 19 09:57

Hibiscus in the lithuanian garden (0)

Autorius Giedra, 2010 05 14 17:06

The great divide (1)

Autorius Giedra, 2010 04 14 14:20

Rejuvenating conifer hedges (1)

Autorius Giedra, 2010 04 01 00:13

Shrubs in mixed borders (2)

Autorius Giedra, 2009 11 16 14:23
RSS

Top 5 topics

www.flickr.com
This is a Flickr badge showing items in a set called My garden. Make your own badge here.