Gardeners corner- May 2024

 

This Spring, the UK has been plagued by a cold, wet April – and I have been plagued by unstable joints, which has limited my gardening efforts somewhat. I wonder what the equivalent gardening answer might be for “strong bones, weak ligaments” – sadly, I doubt that adding bonemeal, seaweed or organic matter to my diet is likely to help.

 

However, my incapacity has caused me to be honest with myself about the reality of gardening in later years. My goal was to reach a point in a couple of years’ time where the planting would be largely finished, so that the garden would be easier to maintain. But if some areas are not cultivated and left as they are, it would make little difference to me and could be more beneficial for the wildlife. Indeed, nature has a way of stopping us from overdoing things one way or another. And while I wait to learn exactly how decrepit I might be, it will do no harm to develop a “plan B”.

 

 

What have I learned this spring: tips, tricks and observations

 

Saffron crocus

 

February proved to be a very busy time in the garden. I installed a couple more raised beds – two of them specifically for saffron crocus (crocus sativus), which shows absolutely nothing until early Autumn, when the bulbs push up long, dark green, grass-like vegetation. The bright purple crocus flowers appear during October – two or three to one bulb- and the long, burnt orange stamens can be carefully pulled off with tweezers, dried on paper towel, and stored in a brown glass jar to add a beautiful, honeyed colour and delicate flavouring to rice, soups and other dishes. A huge number of bulbs would be needed to harvest enough for commercial purposes, but a little saffron goes a long way, it can be expensive to buy, and it is a treat to welcome the flowers just as everything else is dying back. The bulbs can multiply rapidly, hence the few I planted years ago now exceed 100. They can be bought quite cheaply from online suppliers and will grow anywhere with good drainage, preferably in their own space. We live about 8 miles from the old market town of Saffron Walden, which takes its name from the cultivation of saffron for dyeing cloth and wool.

 

Fruit and Vegetables

 

I am not a fan of sowing summer veg seeds until early April; this is because my greenhouse is unheated and there isn’t anywhere indoors suitable for raising seedlings. Usually, the seedlings catch up with my friends’ sowings in February and March; sometimes they even have to slow early growth down (by reducing the available light) until it is warm enough to plant them out.

 

My sowing spree over Easter this year, however, yielded very mixed results in the greenhouse due to the lower temperatures and higher humidity. Some of the tomato and pepper varieties failed to germinate at all, whereas sowing two cucurbit seeds to a pot (the idea being to weed out the weaker) has led to twenty menacingly strong cucumbers and almost as many courgette plants.

 

Given Peter’s propensity to cook up large quantities of produce, he can look forward to making plenty of courgette, lemon and ginger jam. Likewise, we will have enough cucumbers for a crate of Pimms. But I cannot disappoint him with an inadequate supply of tomatoes and peppers, so I have bought some plug plants to supplement those grown from seed. There are still some good offers available on summer plants including vegetable plugs and plants (see the links below), but you will have to act fast!

 

 

Citrus and Fig Trees

 

For those fortunate to live in frost-free climates, you are probably wondering why I go to the trouble of growing citrus and figs. Certainly it is an expensive and unreliable way of obtaining the fruit, although the Brown Turkey fig (regarded as one of the hardiest) has surpassed itself each year in terms of yield. It lives in a pot on a SW-facing walled patio, and my only interference is to prune 1/3 of the branches by 2/3 each spring, and to give it regular seaweed drinks during the summer.

 

I acquired two new figs last summer – Panachee has attractive lemon-and-lime striped fruit, and Goutte D-Or is a very sweet fig. Both varieties are frost sensitive. However, I have discovered that exposure to colder temperatures is a necessary part of the fig tree’s life cycle, and that the more mature figs are protected by their thicker bark. This explains how a tree that thrives in high mediterranean temperatures can cope equally well with cold winters. The weblink below contains a lot of useful information and videos about overwintering figs and the importance of winter dormancy. I will be following this advice while raising these two young trees through their first few winters in the UK:

 

https://www.figboss.com/post/dormant-fig-tree-can-fig-trees-survive-frost

 

Something very interesting has happened to my citrus trees while overwintering in the unheated greenhouse. Last autumn, I decided to draught-proof the colder side of the greenhouse with a roll of silver bubble wrap (more commonly used to insulate behind radiators). The trees sat about 6” from the bubble wrap and were given rainwater and winter feed very sparingly.

 

The rest of my 6’ x 8’ greenhouse was packed with 15 big pots of canna, the two figs, a pair of fuchsia trees and an assortment of cuttings. The vent is always open 2”-3” except when snow or high winds are forecast, mainly because citrus are dense evergreen trees that need good humidity and airflow.

 

I always expect some leaf loss and yellowing over winter, however this year all of the citrus (lemon, sweet orange and lime) continued to grow, putting on significant leaf growth and developing a lot of flower buds. The backs of the trees had grown just as much as those in direct sunlight and had more flowers open for the bees.

 

My working theory is that the silver foil reflected enough heat and light to keep them growing, even while the temperature would have been close to zero during winter and on many nights; in which case they must be more sensitive to light than temperature. Higher humidity throughout the winter may also have helped; evergreens can easily drop their leaves if the air is too dry. The trees were moved outside this weekend and I have decided not to thin them out at least for the time being. During a recent visit to Portugal, I noticed that the foliage of the many orange trees grown in the Algarve is so dense that some of the developing fruit is completely hidden.

 

There is nothing quite like harvesting your own lemon in the UK- but it does require patience because the fruit ripens during the cooler months!

 

Japanese Acers and Roses

 

Our cold, wet April has given us a splendid display of Japanese Acers this year. They were planted in containers a couple of years ago, and the dry summers were challenging in terms of keeping them watered (preferably, rainwater) and sheltered from hot sun. I was surprised to observe so-called slow growing acers virtually doubling in size this year.

 

They are wonderfully colourful and the fine “dissectum” leaves are beautiful to the touch. I didn’t expect them to need bigger pots for another couple of years at least, but that’s a nice problem to have! They are easy to grow, but need protection from cold winds, shade from the afternoon sun, a loamy, moist soil - and a position where your acer can be admired.

 

I seem to be raising a lot of peonies and roses from small beginnings. Pieces of peony roots have become sizeable plants (worth £15-£20 each) after about 3-4 years of being left undisturbed in a sunny, well-draining bed.

 

Roses are trickier, but I am getting better success now with the bargain packs of 5 or 6 bare root roses ordered from Gardening Express. Most of these packs contain smaller varieties bred for commercial cut flowers; they have names that are not seen for sale anywhere, but they produce lovely blooms for the vase or border.

 

Occasionally the varieties sent out will be the very opposite – shrubby, romantic old varieties like Mme Alfred Perriere, or William Lobb. These can swamp a small garden, but each will make a fabulous gift for any rose lover who has 5-6’ to spare. Having initially overlooked old roses as more difficult to care for, frankly there is little difference between any of them in terms of care. The key is to Google each rose BEFORE planting it out, to learn as much as you can from a handful of reliable websites about its growth habit and preferences.

 

These “bargain bare root” packs of roses do not yet have the 2–3-year root structure of those typically sold by rose breeders and distributors which are sold as cheaper “cool season” alternatives to their potted counterparts; both of those are sufficiently mature to withstand planting into a permanent position. By contrast, these younger roses are still babies. I have learned not to plant them straight into a rich soil (like John Innes No.3) with the usual handful of bonemeal, but to treat them more like rooted cuttings that need potting on. This means using a freer draining and more open organic potting mix, no additional feed, and a little dip of the roots into mycorrhizal fungus (Rootgrow or similar) when planting.

 

I tend to use individual rose pots which are fairly deep. Importantly, do not let the soil dry out during the summer; feed the roots with a weak monthly liquid feed, and while there will be some top growth, don’t expect many flowers (if any). Remember to water the soil only, as wetting the leaves regularly can encourage disease. Similarly, I don’t use mulch in case this invites disease.

 

Prune the canes back to 10” when the rose enters dormancy in November. By Spring next year, you will have potted roses with the same maturity as those bought from rose suppliers – and then you can plant them out as if you had paid £20 for each one.

 

There is another advantage to growing older varieties of roses which I hadn’t considered. According to recent research, many modern hybrid roses contain only a narrow selection of genetic material compared with those that are older, or mainly bred from older varieties. We are doing the rose world a favour by growing some of the latter.

 

Similarly, a friend who is responsible for the planting of a heritage rose garden has also been advised recently to introduce a few modern varieties to help boost diversity (and to introduce some repeat-flowering roses into an otherwise flowerless display after the magnificent single flush in June). The full study is free to read through this link if you fancy a change from grappling with human DNA!

 

https://www.biorxiv.org/content/10.1101/2023.06.22.546162v3

 

And finally, here is a fascinating video explaining the construction of a family tree showing the main varieties of roses. You don’t even have to be a fan of roses to enjoy this - and there are quite a few similarities with human family trees!

 

https://www.youtube.com/watch?v=1g0Dl7jap0o

 

 

Links to more offers (it’s peak season for discounts – so don’t delay!)

 

https://www.thompson-morgan.com/

 

https://www.jparkers.co.uk/offers/

 

https://www.sarahraven.com/sale

 

Also see the gardening offers in the main newsletter.