Flowers, Gardening, George, How To, Infographics, Planting, Plants

No plants will survive very long without good watering, and it’s even more crucial for potted plants. They may not have the same access to rainwater, drainage or natural water reserves depending on where they are placed. So here is our handy infographic to remind you how to water pot plants for great growing!

If you’re looking to give your potted plants a fabulous new home, then you’re in luck. At Primrose we have an incredible selection of all kinds of planters available.

How to water pot plants

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Catch up on the previous post in the series: How to Repot a Plant.

Next up is Part 4: How to Choose the Right Planter for Your Garden, coming soon.

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.

Gardening, George, Grow Your Own, Hedging, How To, Plants

Caring for topiary

Growing topiary is one of the most magical arts you can master as a gardener. We all love the huge hedge animals and blooming box clouds. But maintaining and caring for topiary plants can be a lot of effort, so we’ve broken down the steps into our top tips. Keep this checklist handy as you get to work on your creations!

  1. Plant your high hedges wide as they’ll need a lot of root space.
  2. Topiary needs aerated soil so make sure it doesn’t become waterlogged. Use good compost, bark mulch and grit.
  3. Feed your plants with slow release fertiliser granules, and Growmore once every spring.
  4. Water regularly over summer and give a light watering in winter.
  5. Sterilise your cutting equipment with antibacterial spray to avoid transfer of disease.

Clipping topiary hedges

  1. Clips your plants into shape once or twice a year. During summer is the best time to do this – start after frost season is definitely over and finish up by September.
  2. Only cut the topiary on an overcast day as bright sunlight will scorch the leaves.
  3. Experts recommend trimming first with power tools for speed, then cleaning up with sharp shears.
  4. If you’re training growing branches then use soft twine so it doesn’t cut into the wood.
  5. Watch out for signs of disease. Box hedges are particularly affected with box blight and box suckers. Yew can be hit with phytophthora root rot.
  6. If your topiary has been neglected then hard prune it in early spring to get it back into shape. Then give it plenty of feed and mulch.

Topiary maintenance

We hope these tips will get you started on the path to topiary perfection. If you have any other points on how to care for topiary then please share in the comments below!

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.

Gardening, George, Greenhouses, Grow Your Own

Greenhouses are a staple of English gardens and an aspiration for all serious home-growers. But how do greenhouses work and what benefits do they provide for your plants and vegetables?

How do greenhouses work

What is a greenhouse?

A greenhouse is an external structure for growing plants, primarily made of a transparent material like glass or polycarbonate panels. They’re used in professional agriculture for growing huge volumes of crops, as well as by enthusiasts in their own back gardens. Inside you get a stable, warm environment that makes cultivating fruit and vegetables much easier throughout the year.

How do greenhouses work?

Greenhouses work by letting in as much light as possible then trapping this as thermal energy. The transparent walls and roof of the greenhouse allow all the visible rays of sunlight to pass through. This light heats up the air and objects (like the plants and soil) inside the greenhouse. But the glass also acts as an insulator, so this heat is locked inside the structure, keeping the temperatures warm all through the day.

Greenhouses are great at moderating a stable temperature. Matter within the greenhouse like soil and water absorb the thermal energy from sunlight and release it slowly, so they keep the greenhouse warm even after the sun sets. If the greenhouse contains lots of soil, the iron content within this has high enough thermal mass to regulate the temperature in this way with gradual heating and cooling throughout the day. Since the greenhouse is a closed structure, there is no breeze to disperse the warm air.

So the temperature remains constant, generally much warmer than the cold snaps we face outside, and your plants stay happy. They get all the sunlight they need to grow healthily and are sheltered from any harsh weather.

What are greenhouses used for

What are greenhouses used for?

Greenhouses effectively allow you to cheat the weather. In Britain we often have unreliable seasons at best, with cold winters and short summers. With a greenhouse you can extend the growing season – for example by sowing seeds earlier and growing vegetables like French beans and cucumbers for most of the year. Outside they would get too cold, but in the greenhouse they are protected.

The warmer environment in the greenhouse also means you can grow plants maladapted to our climate. Exotic species, such as melons and sweet potatoes, can thrive under the hot glass and delicate plants that would normally die in the winter frosts can be kept safe.

What are the benefits of having a greenhouse?

  • You can extend the growing season.
  • You can keep crops safe from pests within the physical structure, and so minimise the use of chemical pesticides you need to spray on produce.
  • You will protect plants from excessive temperatures (both cold and hot) and extreme variations in weather.
  • A greenhouse offers protection from strong winds which can damage delicate plants.
  • Shelter from rain and snow allows you to manually regulate how much water each plant is getting. This can be made easier with irrigation systems.
  • Temperatures can also be regulated with ventilation systems like auto vents to open windows and let air in, or shading to reduce light getting in during the peak of summer.
  • You can grow plants that wouldn’t normally survive in your climate.

Benefits of a greenhouse

Tips for keeping plants healthy in a greenhouse

While your plants will be kept warm and protected from the elements, you need to make sure they still get all that they need. Since they won’t receive water naturally from rain, you must remember to water regularly or set up an irrigation system to do this for you. It’s also worth setting up greenhouse guttering and a waterbutt to harvest rain falling on the roof.

During the summer months, the greenhouse can sometimes get too hot, which isn’t healthy for everything growing. So be sure to open a window or door if it gets too stuffy. You can also use a ventilation system like louvre windows or automatic vent arms to manage this for you. If excessive sunlight is causing the greenhouse to heat up uncontrollably, then hanging or spraying temporary shading on the roof windows can alleviate this.

Your greenhouse will also need taking care of to make sure it’s at its best year after year. This includes things like an annual deep clean, sterilising pots and checking for damage. You can read more in our greenhouse maintenance guide. Also make sure that you keep on top of pest control in your greenhouse.

Lacewing greenhouse

Different types of greenhouse

Thankfully there’s not just one type of greenhouse to satisfy all gardeners. If you have space, then it’s worth getting the biggest freestanding one you can to maximise your growing area. But if space is limited then you can get a lean-to greenhouse attached to the side of your house, which offers the same robust frame and panels. For allotments and patio gardening, mini greenhouses and cold frames provide very compact space for crops, and can be portable too.

Read more about how to choose your greenhouse.

So we hope you now have a better understanding of how greenhouses work and why they’re such an invaluable treat for hobby gardeners and pros alike. If you’re interested in buying one for yourself, Primrose has a great range of high quality greenhouses available.

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.

Composting, Gardening, Jorge, Plants

mycorrhizal fungi
A mycorrhizal fungus as viewed under the microscope. Picture credit: Dr. David Midgley (2007) licensed under CC BY-SA 2.5.

Mycorrhizal fungi rootgrow has become a common feature of garden centres of late, and has been advertised as a product that can greatly boost your plant’s health. But does it really work? And when should I apply it?  Before delving into such questions, it would be worthwhile to explain what are mycorrhizas.

What are Mycorrhizae?

The etymology of Mycorrhiza comes from the Greek mykos “fungus” and riza “root”. And this is precisely what mycorrhizae is, a symbiotic relationship between fungi and plants. It occurs in nearly all plant life on land and is thus suspected of being one of the key factors that allowed plants to colonise the land.

The relationship is symbiotic as the fungi and plant provide one another with nutrients that each are maladapted to garner independently. It has its origin in the fact each are different types of organisms, with fungi being heterotrophic and plants autotrophic. Heterotrophs, such as humans, absorb their nutrients from organic sources, but can’t produce energy from inorganic sources. Autotrophs, on the other hand, can produce energy from inorganic sources such as sunlight. Plants do this through the process of photosynthesis that produces carbohydrates. As autotrophs, plants also find it difficult to absorb essential nutrients such as nitrogen and phosphorus.

endomycorrhizae
Mycorrhizal fungi located inside a flax root’s cortical cells as viewed under the microscope.

And this is where the fungi come in. The fungi that can easily absorb such nutrients interacts with the plant’s root system, which the plant willingly allows, providing such nutrients in return for the carbohydrates that itself cannot produce.  It does this through expanding its roots’ surface area that can absorb nutrients and water. They also provide the additional benefit of increasing a plant’s resistance to pathogens, preventing root disease.

As a side-note, the mycorrhizas were once divided into broad groupings, the ecto (outside) and endo (inside) varieties, with the former (usually) coating the root cells and the latter intermeshing into the plant root cells; although today they have been divided into new sub-categories or superseded with new typings. The endo varieties are difficult to spot, while the ecto varieties presence may be hinted at with the appearance of toadstools, or coated, oddly-branched roots.

The Leccinum aurantiacum – an ecto variety of mycorrhizal fungus. Picture Credit: Tomas Čekanavičius (2006)  licensed under CC BY-SA 2.5.

Do I Need to use Mycorrhizal Rootgrow?

It is suspected that neither fungi nor plants could survive in many situations without such a relationship. Mycorrhizas is fairly ubiquitous throughout the soil, and can infect a wide range of plants, so it is highly probable that suitable plants will become infected in their lifetime. There may be some exceptions to this, such as heavily cultivated soil and isolated rocky outcrops, but more on this later.

Scientifically, there is little evidence supporting the use of mycorrhiza rootgrow. The British Standards Institution, which produce technical standards on an array of products, does not recommend using the rootgrow for planting trees as a matter of routine. At Texas A & M University, a team grew plants in soils with and without mycorrhizas and found that the infected plants grew slightly better at the planting-out stage, although any advantage disappeared completely after two seasons in the ground. This was because all the plants ended up infected with mycorrhizas anyway. Finally, a test by Which? Magazine found that the potting compost brand that contained mycorrhizas performed poorly, although such an outcome may be down to other factors.

So are mycorrhizas products any good at all? In all probability mycorrhizas products will be unlikely to confer any long term benefits to your plants, unless you have good reason to suspect that your soil is deficient in mycorrhizas. (It is important to check that your plant can benefit from mycorrhizas in the first place.)

Heavy use of phosphorus in agriculture reduces the incidence of mycorrhiza in the soil. The element is also used to ignite matches.

As already stated, heavily cultivated ground may reduce the occurrence of mycorrhizas. This is because fungicide is naturally destructive to fungi, although, interestingly, it is phosphorus-rich soil that is especially detrimental to mycorrhizas. Mycorrhizas usually function to gather this rare resource for plants, but an abundance of it, usually created by fertiliser, actually suppresses it. Why this is the case is unclear, although it can be in a sense expected, as messing with the ecosystem can have untold effects. Sadly, in this case using mycorrhizas rootgrow is unlikely to have any effect, as if the soil is not conducive to mycorrhizas, the best option will be to stop using phosphorus rich fertilizers, and wait for the mycorrhizas to return naturally.

There may be reason to use mycorrhizas in some cases, perhaps for isolated plants, and plants that are indoors (although such cases are unlikely to be common).

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.