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, and well 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.

George, How To, Infographics, Planters, Planting

Picking the perfect planter is all about balance. You need the right size for your plant, with room to grow, a material that helps with drainage and keeps the pot movable, and of course a design in keeping with your vision. Weigh these factors up and you’ll be well on the way to learning how to choose the right planter for your garden with the infographic below.

When you’re ready to dive in, head over to our collection of containers where you’re sure to find the planter that’s just right!

How to choose the right planter infographic

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Thanks to our new design intern Becky for creating this beautiful infographic!

Make sure you check out the previous infographic, How to Water Pot Plants. Next up is How to Plant Potatoes in Containers!

George at PrimroseGeorge works in the Primrose marketing team. As a lover of all things filmic, he also gets involved with our TV ads and web videos.

George’s idea of the perfect time in the garden is a long afternoon sitting in the shade with a good book. A cool breeze, peace and quiet… But of course, he’s usually disturbed by his energetic wire fox terrier, Poppy!

He writes about his misadventures in repotting plants and new discoveries about cat repellers.

See all of George’s posts.

Allotment, Dakota Murphey, Gardening, Grow Your Own, Planting

Growing your own food is not only the obvious answer to lowering food miles and a cheap way to produce tasty fruit and vegetables for your own kitchen, it’s also a growing (!) hobby for many people. In fact, having raised beds in your garden or taking on an allotment on the edge of town can be one of the most rewarding things you will ever do.

Vegetable gardening
We’ve come up with 7 compelling benefit of growing your own – and no doubt you can probably add a few more of your own.

1. Improve your mental and physical health

According to the National Allotment Society (NAS), ½ hour’s allotment gardening burns around 150 calories. That’s about the same as low impact aerobics, but with the added benefits of fresh air and working with the land.

What’s more, a vegetable patch or allotment can be your haven, somewhere to escape to from the hassles of everyday life. Just spending a few hours pottering around in the garden is a great natural stress reliever.

2. Discover the community spirit

Whether you have an allotment or a few vegetable beds at home, you’re not alone! There’s a whole movement of people discovering the joys of Grow Your Own. Why not get to know your fellow gardeners, meet up at Seed and Plant Swaps, share your interests and trade handy tips and tricks – and make new friends.

Vegetable gardeners are a friendly folk, always willing to give advice to newcomers, which is invaluable for learning the ropes.

Vegetables from the garden

3. Learn something new

Learning about the different varieties of fruit and veg and how to grow them in your soil is a process that never ceases to be exciting. Read around the subject, share any problems with the rest of the gardening fraternity and ask the old guard for gardening advice, then use trial and error to see what you can achieve.

If you can involve your children or grandchildren and pass on your skills and enthusiasm for allotment gardening to them, so much the better. It’s a great way to help children understand where food comes from.

4. Reap bountiful rewards

There’s a huge sense of personal achievement in growing a fruit or vegetable from seed in your garden or allotment, knowing exactly where it’s come from, how it’s grown and what it’s been treated with.

But surely the real beauty of growing your own is that the fruits of your labour are tangible – and you can eat them! There can’t be many more directly rewarding activities than harvesting your home grown veg, then create and serve up delicious dishes in your kitchen.

Home growing

5. Wow your taste buds

It is a (sadly surprising) fact that most of us only come to realise how delicious fresh fruit and veg can taste when we compare our home grown produce with mass produced supermarket foods. Once you’ve tasted the difference, there’s no going back.

Harvested fresh from the ground, potatoes and carrots taste more earthy, tomatoes plucked straight from the vine have a richer flavour, while sweetcorn cooked straight after picking tastes incredibly sweet.

6. Save money

Not only are home grown fruit and veg much tastier than their shop bought equivalents, they’re better quality and cheaper too. With some careful planning and regular gardening exercise (which will make your gym membership redundant), you can feed the whole family with fresh produce for most of the year.

Also, rather than hunting down unusual ingredients in the supermarkets and pay through the nose for them, why not grow new and different varieties yourself? For the price of a packet of seeds (try Seed Parade), you can try delicious Japanese radishes or Chinese artichokes, Red Russian Kale or Purple French Beans or any of thousands of other fabulous varieties out there.

Home grown produce

7. Help the environment

According to the NAS, even 1 square metre of land is enough to support hundreds of different wildlife species. Your ‘grow your own’ efforts will help to create the right habitat for bees and other wildlife to thrive, without which our ecosystem will deteriorate, crop yields will decrease and our planet will suffer as a result.

If you have the space, why not incorporate a wildflower meadow into your garden, add a pond, a beehive or a chicken coop?

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.