Growing Sweet Marjoram

Latest Update 1st August 2016.

Sweet Marjoram
  • I have grown Sweet Marjoram from seed as a culinary herb for a few years now.
  • I use it with other herbs to make a general purpose condiment of crushed dried leaves.
  • Its happy in my garden and quite at home in our hot dry summers.
  • Its largely pest free, and the only precautions taken are to spray the foliage with aerated compost tea once a month and feed the soil with thermal compost once a year.
  • Most pollinating insects in my garden are attracted to the small clusters of white flowers, and the aromatic scent of the leaves deter airborne pests.
Details.
  • Family:                                                     Lamiaceae.
  • Garden bed type:                                       Drip line irrigated organic bed.
  • Recommended soil pH:                              6.0 - 8.0.
  • Minimum Sun per Day:                               3 hours.
  • Plant Spacings (centres):                           300mm.
  • Good Companions:                                    Beneficial companion for all plants.
  • Climate:                                                   Warm Temperate.
  • Geographic Hemisphere:                            Southern. 
Nutrition.
  • This food is low in Saturated Fat and Sodium, and very low in Cholesterol. 
  • It is also a good source of Phosphorus and Potassium, and a very good source of Dietary Fiber, Vitamin A, Vitamin C, Vitamin K, Vitamin B6, Folate, Calcium, Iron, Magnesium, Copper and Manganese.
  • More from nutrition data.self.com.
Notes. 
    Growing Conditions:
    • They prefer sandy soil but grow well in most healthy organic soils. 
    • They grow well in hot dry conditions and resist drought. 
    • Sweet Marjoram needs well drained soil and full sun.  
    • They are light feeders and don't need artificial fertilisers. 
    Soil Preparation. 
    • In Spring, clear a space for Sweet Marjoram by removing old mulch, dead leaves and unwanted organic material.  Choose a place where Sweet Marjoram has not been grown for several years.
    • Apply a 60mm top dressing thermal compost and cover with 50mm of fresh organic mulch.
    Growing Instructions. 
    • Sweet Marjoram is a perennial plant grown from seed.
    • Sow seeds in August on the surface of an organic seed growing mix in a mini pot, and cover lightly with sieved seed mix.
    • Soak the mini pot for an hour in a tray containing 10mm of water (preferably rainwater).  The water will wick up into the soil without flooding it. 
    • Sink the mini pot up to its rim in a propagator's wicking media.  This will keep the soil moist until the seedlings are ready to transplant.  Protect the seedlings against frost if necessary. 
    • After 4 weeks the seeds are transplanted individually into organic potting mix in jiffy pots and returned to the propagator.
    • After a further 4 weeks plant the seedlings in the prepared soil after clearing spaces in the mulch.
    • Return the mulch as soon as the Sweet Marjoram is established.
    • Apply a foliar spray of aerated compost tea every 4 weeks when the other edible plants are sprayed.
    • If left to its own devices a Sweet Marjoram plant will become woody after a couple of years.  To prevent this you should prune the plant in spring.  Cut the green growth back by 1/3rd but don't cut back into old wood.
    Harvesting and Storage. 
    • Sweet Marjoram can be harvested at any time, but don't strip the leaves too much or you could set the plants growth back some time as it recovers.
    • Begin using the leaves as soon as the plant is large enough to spare some.
    • You can dry Sweet Marjoram in a dehydrator after stripping the leaves from their branches.  Once the leaves are dry, crush them and store them in an airtight container. 
    Organic Pest Control. 
    • Slugs and snails.
      • I grow my herbs in a drip irrigated raised bed, and run copper tape around it 100mm off the ground.
      • Copper tape is a very effective barrier as the slugs and snails get a small electric shock when they come into contact with it, and they retreat to less hostile surroundings.
      • Occasionally I get one or two juvenile snails in my raised beds.  I believe they get into the bed as eggs though the compost heap.  When this happens, I use a few iron chelate snail baits to round them up.  These bates are approved for use in organic gardens, but I only use the bare minimum to do the job.
    • Greenhouse whitefly.  
      • A foliar spray of aerated compost tea helps strengthen the plants foliage against whitefly damage, but check your crop regularly to be sure you are rid of them.
      • Spray the whole plant with organic horticultural oil if it becomes infested as early in the whitefly's life cycle as possible.  
      • Spray again in a few days to ensure second generation whitefly do not survive.
    • Aphids (greenfly).
      • Use the same methods described above for whitefly.
    • General.
      • Regular applications of aerated compost tea boosts the natural defences of plants by colonising their leaf surfaces with beneficial microbes.  The microbes defend the plant against airborne pests and diseases.
      • Similarly, proper soil preparation including regular applications of home made compost boosts the community of beneficial microbes, which defend the plants roots against plant pathogens.