Gardening, Jorge, Weeding

To many gardeners, weeds are a recurrent annoyance that you have to put up with as a fact of life. They can interrupt your otherwise perfect lawn or stifle your crop yields, and at worst cost thousands of pounds in damage as in the case of the Japanese knotweed. The effects of weeds are extremely costly, and it has been estimated that up to 10% of agricultural production may be lost because of them. But, weeds play a key role in transforming inhospitable environments into new habitats, and without them we would not exist today.

Weeds are good for the ecosystem

Weeds are important as they play a key role in transforming barren earth into rich fertile soils. They are, in effect, pioneers as the first plants to colonise a piece of land and improve its soil for the development of more complex ecosystems. They do this in a number of ways.

Weeds act to shield the soil from the sun, protecting both insects and microscopic organisms from sunlight. Their roots stabilise the soil, creating a secure environment for life, while their stems trap organic matter, which breaks down in the soil and provides sustenance for insects. Weeds with long roots draw up nutrients from deep in the ground, improving the quality of the surface soil. When they finally die, they decompose into humus which increases the soil’s moisture and nutrient retention, but decreases its bulk density, which is important in the early stages of soil development.

Curled Dock with its deep taproot draws up nutrients to the surface soil. Picture Credit:  Oliver Pichard (2007) licensed under CC BY-SA 3.0.

Back hundreds of millions of years ago, the Earth was very different, as a barren rock with water running over the surface with no defined course. Key to transforming the Earth were plants that broke down rock into minerals and soil, which it then held in place with its roots. This led to the development of river banks that channeled water in a regular fashion. Periodically, such rivers would flood, depositing sediment over large areas, which allowed trees to take hold. Such larger plant life would produce even more debris that would block up rivers, causing more flooding, a process that would lead to the emergence of larger complex ecosystems.

The predecessors to the plants that we consider weeds today played a key part in all this as early pioneers that ensured soil stability in such flooded areas. Important to this were rhizomes that allowed plants to cope with severe disruptions in their environments. Rhizomes are branching stems that grow horizontally, often through the soil, and are the feature that makes weeds so durable, as even if you destroy a plant’s matter above ground any surviving rhizome in the soil will lead to its reemergence. Not only does the rhizome store energy, allowing a plant to reemerge in favourable conditions, the stems allow the plant to propagate vegetatively,  producing a clonal plant.

An artist’s (Édouard Riou) impression of early Devonian land flora.

One early example of a plant that helped stabilise the earth’s environment was the Drepanophycus from the Devonian Period, which was unearthed by a team from Peking University. It was discovered preserved in paleosols – fossil soils – that within were multiple sequences of sediment formed by river channels, which were periodically wiped out by floodplains. The plant grew continuously due to its rhizomes and trapped sediment, enabling stable soils to develop. And after the floods, the plant would reemerge, growing through the newly deposited layers of sediment. The team calculated that the plant had a modest, but significant role, in reducing soil erosion. It is believed to have carried out this function for centuries.

Weeds constitute an interesting case study in evolution and humanity’s effects on the environment

Today weeds constitute a fascinating area of study due to their phenotypic plasticity, or simply put, their ability to change in response to changes in their environment. An example of phenotypic plasticity may be a plant’s ability to utilise more or less water (in photosynthesis) depending on its availability. Phenotypic plasticity is especially important for plants that do not have the ability to change their environment (as in the case of many animals, such as humans), and weeds are especially adaptive as agricultural practices make it necessary to be highly responsive if they are to survive.

Weeds evolve quickly in three principal ways: through adapting to continuous habitat disturbance, emerging in part from agricultural practices; through reproducing with different cultivars (groupings of plants selected for certain characteristics) as to produce hybrids; and finally through returning to natural seed dispersal methods when certain domesticates (plants dependant on humans for survival) are abandoned. This has led to the survival of certain species that are extremely difficult to control as they have developed such traits as early germination, rapid growth from seedling to sexual maturity, and the ability to reproduce both sexually and asexually. Fascinatingly, a 2013 study carried out by Fudan University of Shanghai found that if genetically modified crops did crossbreed with their weedy cousins, the resultant weeds would have higher rates of photosynthesis, more stems and flowers, and significantly more seeds. So, in the future, weeds may become even more troublesome than they are now.

Centuries of grazing has altered the landscape, benefiting plants that can’t be consumed by livestock.

As such, the battle between farmers and weeds constitutes an interesting case study of evolution in action and the selection effect humans exert on plants. There are many examples of the latter. For example, tilling tends to favour annuals at the expense of perennials, while no till systems benefit perennials. Frequent mowing, on the other hand, tends to benefit weeds that grow horizontally. The grazing of livestock has led to an increase in noxious thistles and other inedible species on the rangeland. In some cases, weeds have even begun to replicate crops in their appearance and life cycle as in the case of barnyardgrass growing with rice.

Weeds perform an important signalling function

Weeds can tell you a lot about your garden, providing information about what is best to grow. If your weeds multiple rapidly it is likely that your soil is extremely fertile, and that you do not need fertiliser. If not, it may be wise to start growing forerunners such as onions before moving onto more difficult crops. If the amount of weeds is diverse, it is likely that you can grow a wide range of plants in your garden. If not, it will be worthwhile to ascertain the soil type. And weeds can do this too. Very acidic soil will produce sorrel and plantain but no charlock or poppy, while chickweeds is sign of neutral pH. High levels of nitrogen can be ascertained by nettles, ground elder, fat hen and chickweed. Compacted soil is noticeable for silverweed and greater plantain, while creeping buttercup, horsetail and silverweed may indicate wet soil with poor drainage.

Weeds constitute a good source of nutrients

Dandelion leaves are high in vitamin a and k and can be useful addition to a balanced diet.

Many weeds are edible and good for you. They are also effectively free and environmentally friendly. In the UK, nettle soup comes to mind as one famous example. Back in the Middle Ages, ground elder was grown as a crop and was believed to cure gout – hence its alternative name goutweed. It possesses a nutty flavour and can be added to salad. Many health blogs recommend dandelion as a superfood, which can be found everywhere. Sorrel and horseradish can both be made into sauce and the latter is often used with beef. There are many great blogs dedicated to eating and cooking wild food. Why not check them out for yourself?

A concluding thought

Perhaps, our obsession with weeds tell us more about ourselves than we think. Why are we pursuing them with such vigour? Instead of hastily striving for a perfect world without weeds, perhaps we should examine why they are there in the first place. After all, a weed is a plant whose virtues have yet to be discovered (Emerson, apparently).

Jorge at PrimroseJorge works in the Primrose marketing team. He is an avid reader, although struggles to stick to one topic!

His ideal afternoon would involve a long walk, before settling down for scones.

Jorge is a journeyman gardener with experience in growing crops.

See all of Jorge’s posts.

Dakota Murphey, How To, Weeding

Every day when you come home from work you look up and notice the dark green patches of moss growing on your roof. It’s an eyesore and you’d like to get rid of it. You’re free this weekend and decide it’s the perfect odd-job for you to tackle. But before you rush into the garage, grab you ladder and shimmy up onto the roof, read on, as we’ve come up with some great tips to help you get rid of that moss safely and easily.

Tackling unsightly moss

What is this stuff we call moss?

Moss is a green, flowerless plant that has no true roots. It grows in low mounds or rounded cushions in shady, damp and wet habitats – it loves dark, cool, moist areas. Because it has no root system, it needs a damp environment to thrive. When leaves and grit are blown onto a roof and are lodged there for some time, they begin to decay and this provides the perfect ‘growing bed’ for spores of lichens, weeds and moss that are carried in the wind and blown onto them.

Should we clean moss off our roofs?

Some experts say that moss doesn’t cause a problem, but many others differ. ‘Moss only needs to be removed if it causes gutters, outlets, and other drainage points to be blocked, otherwise it can remain,’ say some. But others say that moss shouldn’t be allowed to grow and build up. Why? Because moss build-up could be one of the reasons for roof problems including raised tiles, leaks and damp.

As moss grows and thickens on your roof, it can cause lifting of the roof tiles, and when this occurs rain water can easily pass under them onto the roof timbers of your home and start to rot the wood. Water can also run down the interior walls of your house and cause serious damp and mould problems.

Raised roof tiles are also a danger in heavy winds – tiles can catch the wind like a sail, blow off the roof and cause serious injury to someone below. You’ll also be missing some tiles so there’ll be exposed areas on the roof, and you’ll need to replace these pretty quickly before it rains again. The more moss that grows and accumulates on your roof, the more debris that is trapped there. This invariably results in a build-up of water, and will leave your roof at risk of leakage and rotted timbers.

Roof moss

There are 3 factors that promote the growth of moss:

  • A cool or cold, moist climate combined with dark and/or shade.
  • An acidic environment where the pH level is between 5.0 and 5.5.
  • A hard surface like roof tiles – moss loves growing on these.

How to kill and prevent moss from growing on your roof?

There are a number of things you can do to prevent moss from growing on your roof. Here are some of the basic ones plus a few others you may not have heard of before but do the job very well.

  • Keep the roof out of the shade and in as much sunlight as possible. This may mean removing some tree branches, or even felling some trees.
  • At the crest of the roof ridges, fit some copper or zinc strips.
  • At varying intervals, string some copper wire across the roof, using screws or nails driven into timber on the sides of the roof (don’t drive them into the tiles as they could crack them and cause leaks).
  • Don’t let the dirt build up – keep the roof free of any leaves, dirt and debris.
  • Try to make the area extremely acidic (above a pH 7 level). There are roof spray products on the market you can use.
  • If you’re not exactly sure what to do, then hire a professional moss removal company to deal with the problem.

What shouldn’t I do to remove moss?

Finally, here are 3 key things you shouldn’t do to remove moss:

  1. Pressure washing your roof is not recommended as this can shorten the lifespan of your roof. The high-powered jet spray removes the asphalt tile granules which help protect your roof tiles. Also, if you spray at an upward angle, water will get in underneath the tiles, which can cause damp and wood-rot problems. Other gutter cleaning methods are advised however.
  2. Be circumspect when using acids to remove moss. If the acidic mixture is too strong, or it remains on the roof too long, it will eat away at the granules of your tiles. It’s a good idea to first test the solution on a few spare tiles before applying it to the entire roof.
  3. Don’t try to scrape moss off the roof, as this can result in cracked or broken tiles.

And finally, if you’d actually like to grow more moss in your garden you can read our tips on cultivating moss.

Dakota Murphey

Dakota Murphey is an independent content writer who regularly contributes to the horticulture industry. She enjoys nothing more than pottering around her gardening in the sunshine. Find out what else Dakota has been up to on Twitter, @Dakota_Murphey.

Composting, Garden Tools, Gardening, How To, Plants, Weeding, Zoe

There are mixed opinions about whether you should bother to sterilise your compost. Some gardeners choose not to, which is fine, but we believe there are many benefits to this very simple process:

  1. It kills off harmful bacteriaSome may argue that in turn you will be killing useful bacteria but this is not the case. The only way you will kill of beneficial bacteria is by baking your soil at a temperature that is too high; we talk about this in more detail later. Professional nurseries sterilise their compost, and there’s no reason you shouldn’t either.
  2. It’s proven to keep away pests such as thrips that are particularly annoying when using compost in your home and sterilisation can prevent such unwanted house guests.
  3. Prevention is the solution. Prevent disease in your compost before the problems arise, rather than skipping past the sterilisation stage and then making the situation a lot worse later on.
  4. Sterilised soil ensures that your plant will be happy and healthy, and this means the best optimal growth.
  5. Better safe than sorry. The methods outlined in this blog are super easy to do, and will make sure your compost is definitely safe for your plants. So why wouldn’t you want to give it a go?

    Making Compost

    Outlined here are three easy methods to sterilise your compost from your home:

     

    Oven

    Using your oven at home you can sterilise your compost easily; be warned that baking compost can create a smelly odour, so you may wish to open your windows whilst doing this.

    • Firstly, you need to use moist soil, do not over water the soil however you only want a slight dampness.
    • Use an oven safe tray and fill it with your soil until it is around 10 cm (4 inches) deep.
    • Cover the tray loosely with foil.
    • Put your tray in the middle of a pre-heated oven that’s around 80° For a more accurate result use a thermometer in the centre of the tray and bake between 80-90°c
    • Do not exceed the temperatures stated above, at temperatures above 90°c is when the good bacteria is killed and toxins are produced.
    • Bake for 30 minutes before taking out, make sure to take the foil off and leave it to cool for a while before handling the soil.

     

    Microwave

    The easiest and quickest way to sterilise your compost is with your microwave. We suggest using an old microwave in your garden shed or greenhouse to prevent bringing compost into your home, and this way you can get on with other gardening jobs whilst it’s baking.

    • As before you will need moist soil, but not too wet that it is slushy.
    • Find a microwave safe container and fill this with your soil.
    • Do not use foil in the microwave, instead cover with cling film with holes for the steam to escape or a plastic lid with air holes.
    • For every two pounds of soil will need 90 seconds in the microwave.
    • After it’s pinged, leave the soil to cool before handling.

     

Alternative method:

  • Place two pounds of moist soil in a polypropylene bag
  • Leave the bag slightly open for ventilation
  • Zap in the microwave for 2-2 ½ minutes on full power before removing and cooling

 

Pressure Cooker

  • Start by pouring a few cups of water into the cooker
  • Next add your pans of soil, be careful not to add more than 4 inches, and pop it on the top rack.
  • Make sure to cover these with foil to help insulate the soil.
  • Close the lid for your cooker but make sure you leave the steam valve

For every ten pounds of soil, leave it to steam for 15-20 minutes.

Voila! You now have sterilised soil that will be sure to sprout stunning plants in no time! If you prefer shop bought compost, read our Primrose Guide to Compost for further advice and information.

Sterilised Compost

Zoe at PrimroseZoë works in the Marketing team at Primrose, and is passionate about all things social media.

After travelling across Europe and Asia, Zoë is intrigued by different cultures and learning more about the world around her. If she’s not jet setting, Zoë loves nothing more than curling up with a good book and a large glass of red wine!

She is an amateur gardener but keen to learn more and get stuck in!

See all of Zoë’s posts.

Composting, Gardening, How To, Laura Bennett, Weeding

The constant gardening struggle: weeds. Weeds are a problem that casual and advanced gardeners have struggled with. You are not alone with this problem. The good news is, you no longer have to be in a constant battle with weeds in your garden.

how to win war against weeds

So, how are you supposed to stop them from growing and taking over your garden? Can I really get rid of weeds without using harmful chemicals? Yes, you really can!

Weeds cause your plants to become overcrowded. They deplete the soil of nutrients that the plants you are trying to grow need. They also compete with your plants for the much-needed water and sunlight your garden receives.

What You Will Need:

• Landscape Fabric
• Landscape Fabric Pins
Organic Mulch or Soil
• Boiling Water
• Natural Weed Killer
• Decorative Rocks
• Plants of Your Choice
• A Shovel

De-weed Your Garden

The first step in keeping your garden free from weeds is to remove them from the area you want to work with. Use a shovel to get rid of perennial weeds with their roots to prevent regrowth. If you do not remove the roots along with the weed, the weed will just regrow.

de-weed your garden

Lay Down the Landscape Fabric

The next step is to lay down and prepare your landscape fabric. Make sure the fuzzy part of the fabric is face down. This helps the fabric stick to the ground and not move. Use the landscape fabric pins to hold the landscape fabric in place.

You can use more than one sheet of landscape fabric for a larger area. Make sure the pieces of fabric overlap here and that the edges are secure and leave no spaces for weeds to grow through.

Pro-Tip: A common mistake is not using enough fabric pins. Make sure to use them frequently. There is no such thing as too many here.

landscape fabric

Mulching

After the landscape fabric is in place it’s time to place down your mulch. Make sure you use a layer of mulch that is between 1-2 inches. The mulch prevents sunlight getting to the dirt below. This also helps to stop weeds from growing.

Pro-Tip: Some mulch may accidentally contain weed seeds, so make sure your mulch is coming from a nursery you trust to be weed free.

mulching

Pour Boiling Water

The next step is to pour the boiling water on top of your mulch. This will help kill any weeds that might be in your mulch that you are unaware of. This is also a good time to use your natural weed killer.

boiling water
Using Natural Weed Killer

Most weed killers only require you use them at the beginning of the planting season (Spring) and again at the end (mid-Summer) if you plan to grow in fall as well. If not, there is no need to reapply your weed killer until the next time you plan to plant. You are now ready to start planting.

natural weed killer

More Tips and Tricks

• Pick one day a week for de-weeding if you find the occasional weed still growing from your mulch.
• You can make a mixture of vinegar and water (in equal amounts) to use on weeds. Be careful not to get this on your other plants though.
• Plant close together to not allow weeds any room to grow.
• You can suffocate weeds and decorate your garden by placing decorative rocks on top of them.
• Drip irrigation systems can be used to provide only your plants with water and eliminate the concern of the water evaporating.

Conclusion

The prevention of weeds is the best method of treating them. Anyone can have a beautiful garden free of weeds. It does take some time and effort but is worth it. There are a lot of ways to help keep your garden free of weeds, which can motivate you to garden even more. With nicer weather on the horizon, it is a perfect time to get ready and give gardening a try.

I hope you enjoyed this article. Please share your thoughts about the article in the comments, and share it with your friends if you enjoyed this.

Laura BennettLaura is a graduate of Horticulture and loves nature especially when it comes to flowers and different kinds of plants. She has been a blogger for some years now at Humid Garden.

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