The summer is a time when the English garden comes alive. Many of our most beautiful plants are in full bloom at this time, and our gardens are bursting with life, colour and vigour. However, as well as its abundance, high summer also presents a unique set of challenges for the gardener – especially at a time when extreme heatwaves often take the place of our traditional soft, summer temperatures thanks to global warming. Heritage Glasshouse manufacturer Hartley Botanic has provided some useful advice for Greenhouse gardeners this summer, to help keep their Greenhouse growing at its best. Insight has been taken from Hartley Botanic’s online magazine, which provides a wealth of knowledge and inspiration. Visit:

Watering 101

Watering seedlings in the Hartley Highgrow Greenhouse

During the peak of summer, it is important to keep an eye on watering and the condition of your plants. Maintain a regular regime of feeding and watering with tepid water. Find out if your containerised plants need watering by sticking your finger into the surface of the compost, if your finger is free of compost particles when you pull it out then the plant needs watering. It’s also helpful to learn how to judge this by the weight of the pot with wet and dry compost. When watering, give plants a thorough soak; a light sprinkle will only encourage roots to the surface where they are more susceptible to drought.

Water plants in the evening, poured around the roots not over the leaves and check your containers at least once a day and water even if it has rained. Water according to the type of plant – lavenders, from a Mediterranean climate have a low demand for water but bananas are watered copiously as they lose water through their massive leaves. Putting the ‘right plant in the right place’ helps, too, lavender, cistus, cotton lavender and plants from Mediterranean climates thrive on sandy soils and will only need watering until, established.

Creating a circular ridge of soil around the base of plants allows the water to pool, rather than run off, and adding plenty of well-rotted organic matter to the soil before planting, ensures that water is retained like a sponge. Don’t water established plants unless they are showing signs of stress and if possible, recycle grey water from the bath but not on edible crops and don’t use too much bubble bath, either! Mulching pots with mini bark or gravel will keep weeds down and conserve moisture, too. There are lots of practical ways you can save water. You can also help maintain humidity in your Greenhouse by damping down the floor.

All about Greenhouse shade

A Hartley Botanic Victorian Planthouse Glasshouse with roller shades

When it comes to summer, it is not only lack of water which will cause plants to fail. When it is extremely hot, there is a potent combination of plants not being able to suck water up fast enough (triggering truss-wrecking blossom end rot) and the fierce intensity of the sun magnified by glass. It is often too much for plants, and too much for the gardener themselves! There are a variety of ways to shade your Greenhouse, whether you choose convenient roller blinds or a completely natural DIY solution.

One method is to paint on white shading. A tub to cover a Greenhouse of around 8 x 12 foot will cost just over £8. A downside of doing this, however, is that you need to wipe it off at the end of the season. A canopy of polypropylene shade netting can also be erected locally for specific plants or to cover the house by attaching it to the framework. Keeping netting on the outside means the inside is kept clear for tall crops like cucumbers and melons. In most cases running the netting along one side is sufficient (if your Greenhouse runs East/West for example, you can shade the south side).

A Hartley Botanic Victorian Villa Glasshouse with roller shades

When purchasing a Greenhouse it is sensible to consider including internal blinds as an extra accessory to have installed if you do have the budget. Although expensive, they provide convenient shade in the summer months. Hartley Botanic offers roller shades, in a choice of green or white colours, to fit on its Glasshouses and Greenhouses. These are specifically designed to follow the shape of your Greenhouse and will protect your precious plants from damage caused by the sun and help regulate internal temperatures. Motorised systems with sensors enabled by remote control can also make your life even easier, allowing you to operate your roller shades at the touch of a button! The only consideration with roller shades is their location as they could interrupt taller plants such as climbers or vines.

For a completely eco-conscious DIY solution, which can also be fed back into your garden as mulch or compost, is to create shading yourself using plants such as bracken, rosebay willowherb (Chamaenerion angustifolium) or other tall-stemmed flattish branches of willow or hazel. Simply lie them over your Greenhouse glass and you have instant, natural shade. You can even use plants with huge leaves, such as Giant rhubarb (Gunnera manicata,) which has leaves up to 2m across, or if you have a Greenhouse with a low pitch, grass mowings. Once you have finished with ‘nature’s shading,’ you can then set it to work as mulch, compost material or food for your soil.

Essential jobs for the summer months

Check plants regularly for signs of whitefly, leafhopper, Glasshouse red spider mite, mealybugs and scale insects and treat them with biological controls or environmentally friendly sprays. Keep the Glasshouse free of fallen leaves, flowers and other plant debris to prevent the spread of diseases.

Remove the side shoots from tomatoes as early as possible. Tie in and pinch out the main stems of tomato plants once they reach the top of the support, so all of the energies are channelled into ripening of existing tomatoes.

Harvest crops regularly and train cucumbers and melons onto nets and frames; repot chillies, bell peppers and aubergines until they are in 23cm pots of peat substitute compost. Tie sweet peppers and aubergines to supporting canes if needed.

Harvest crops regularly in the summer months

The following can be sown in July: Basil, Calabrese, Chinese cabbage, Winter purslane, (Claytonia), Chervil, Coriander and Dill, French beans (climbing and dwarf,) Lettuce, Florence fennel, Oriental greens like Pak Choi, Parsley, chard, endive, chicory, beetroot.

Feed citrus with specialist food and continue training climbing plants like Gloriosa superba ‘Rothschildiana’ in a spiral around a tripod of canes, tying in as needed. Keep the pot at the back of the Greenhouse away from the doorway where humidity is higher.

Citrus crops growing in a Hartley Botanic bespoke lean to in Wiltshire

If temperatures are unseasonally low, ventilate using the windows rather than opening the door which causes a draught.

From mid-July you can take semi-ripe cuttings from shrubs like ‘Star Jasmine’, Camellia, Ceanothus, Choisya, Cistus, Convolvulus cneorum, Fatsia, Mahonia and Viburnum. Cuttings taken in summer, rarely need a heated propagator. Keep the compost moist until they are well rooted and shade them from sunshine in hot weather.  Remove any dead or diseased cuttings and leaves that fall. Once the cuttings have rooted, they will need ‘hardening off’ for two to three weeks before potting on or planting out.

Hartley Botanic is an English Glasshouse and Greenhouse manufacturer based in Greenfield, Lancashire. The company was founded in 1938 by brothers Vincent (RHS fellow) and Norman Hartley following their groundbreaking aluminium Greenhouse design, the first time (to our knowledge) aluminium had been used in Greenhouse construction and marking a huge improvement on its wood and wrought iron Victorian forerunners. Today, Hartley Botanic’s reputation has been built on over 80 years of English craftsmanship, creating Glasshouse and Greenhouse structures known for their enduring strength, quality and performance. In February 2017 Hartley Botanic became the only aluminium Glasshouse and Greenhouse manufacturer to be endorsed by the RHS.

It is the Greenhouse manufacturer of choice for leading horticulture organisations, institutions and designers in the UK and worldwide with Hartley Botanic commissioned by the RHS, the National Trust, Kew Gardens, Glasgow Botanic Gardens, Massachusetts Horticultural Society, Oxford Botanical Gardens, Le Manoir aux Quat’Saisons, Blenheim Palace, The Lingholm Estate and Hampton Court Palace…to name a few. Here’s why…

‘Why Hartley?’

Unrivalled. Unparalleled. Unique. There are Glasshouses, and there are Hartley Botanic Glasshouses. Combining inspired design with enduring quality, nothing quite enhances your garden like a Hartley Botanic. The manufacturer prides itself on five key pillars of service which sets it apart:

  1. Beauty and Elegance

The incomparable range of simply beautiful and elegant structures means Hartley Botanic can create designs that are distinctive and unique. The Victorian, Heritage and Modern Glasshouse ranges are so comprehensive you don’t have to go anywhere else to find your beautifully crafted, high-quality Glasshouses from the widest of choices.

  1. Structurally Superior

Every Hartley Botanic Glasshouse is handmade in the North of England to your exact requirements. It is made of the finest materials with unparalleled durability, safety, and beauty. All of the aluminium sections have a structural purpose. Short cuts, such as ‘sticking’ aluminium to glass for aesthetic reasons, are never taken. Hartley Botanic are so confident of the structural integrity of their Greenhouses; a 30-year Lifetime Guarantee is offered.

  1. A Reputation Beyond Compare

Hartley Botanic’s brand heritage and reputation have been built on trust for over 80 years. They have earned an unrivalled reputation for crafting the finest Glasshouses and Greenhouses money can buy through the very highest standards of hard-won experience, craftsmanship and service.

  1. Unrivalled Knowledge and Expertise

There is a wealth of knowledge and expertise built into every Hartley Botanic Glasshouse. Generations of customers have put their trust in the hands of expert, time served, highly skilled craftsmen. Glasshouses of distinction are created from decades of knowledge and care.

  1. Exceptional Delivery of Service

Once your order has been handmade to your personal requirements, and Hartley Botanic’s exacting standards, your delivery and installation will be exceptional. The proud team at Hartley Botanic are there to ensure the process runs smoothly, providing you with the information you need and keeping you up to date throughout.

All Hartley Botanic’s Glasshouses and Greenhouses are handmade, bespoke and made to order. Customers interested in purchasing a Hartley Botanic Greenhouse should visit: or call 01457 819 155 for more information.