Protective Hessian Collars

Tree Ferns

It may not be freezing cold outside at the moment but the team have been keeping a close eye on the long range weather forecast with regard to whether to protect the tree ferns this winter. With the collection now at 15 and, having seen the potential for the overnight temperatures dropping below zero and into the minus', they decide it is better to be safe than sorry and wrap them. For details of the 10 new tree ferns that were added to the college gardens this summer, see blog entry 18th September 'Adding A Touch Of Jurassic To The Gardens'.

Cutting The Hessian

Tying The Hessian Collar

Cutting a large roll of hessian into 15 equal sections sufficient to wrap the thickest trunk they wrap the crown, tie it in place with rope and fill the open top with dry leaves. The protective hessian collars will be removed in late spring, folded, stored and reused again next winter. With all the ferns beside the bridge wrapped they move on to the four in the border beside the Nuffield building which contains the tallest of the collection.

Wrapped

The 11 Tree Ferns Beside The Bridge Wrapped

The Tallest Tree Fern

In order to reach the top of the tallest fern two tripod ladders had to be used to reach the crown, working carefully so as to not knock the fern over, it was only planted two months ago, they wrap the hessian collar around it, tie it in place and fill the space with dry leaves. Protected, the temperatures can now drop below zero!

Leaves To Protect The Crown

Going Back To The Old Ways

The Cutting Down Of The Herbaceous Border Begins

The perennial plants in herbaceous border have put on a beautiful display over the summer and autumn months but are now tired and faded. Ready for their annual cut down, the team use hand shears and secateurs rather than the noisy hedge cutters, as in the previous years, to cut the stems down to the ground. Hedge cutters were first used to cut down the plants in the herbaceous border in November 2011 and, although a much quicker method, there is something quite therapeutic and rewarding about cutting down plants using secateurs and hand shears even though it takes twice as long!

A Pile Of Birch Plant Supports

The birch basket plant supports made at the end of April, see blog entry 2nd May 2017 'Twisting The Silver Birch In To Shapes' were pulled out of the border, placed into a pile ready to be taken to the chipper pile. 

Raking And Collecting Up The Debris

Working through the two borders all the cut down plant material, lifted annual plants, debris and leaf litter were raked in to piles and lifted into the trailer using leaf grabs and pitch forks. The black pourus pipe was pulled out from the border, rolled up and placed into storage until next spring. 

To The Compost Heap And Chipper Pile

Using Hand Shears

Herbaceous Border (L) Cleared

After two days both sections of the border had been cut down and, over the coming days, the congested plants will be lifted, split into smaller pieces and replanted. When this has been completed, and the leaves from the many wisteria that grow up the cottages behind the border have finished falling all over the soil, they will be raked off, the border weeded and forked through before a mulch of leaf mould added over the soil.

Herbaceous Border (R) Cleared

Cleared, Waiting For The Wisteria Leaves To Fall

The Fruit Of The Acca, Feijoa (Pineapple Guava)

Acca sellowiana

In front of the south facing wall of the Nash Building, in a border full of shrubs, there is a quite plain, scruffy looking shrub with grey-green leaves. However, upon looking into the dense covering of leaves, the shrub, Acca sellowiana (also known as Feijoa sellowiana or Pineapple Guava) is laden with green, waxy skinned, egg shaped fruit. Planted several years ago this is the first time it has produced fruit.

The Fruit Of The Acca, Feijoa

Ripe when they drop they are similar in size to a Kiwi fruit. A strange mix of flavours but delicious they can be used in crumbles, cakes, jam, salsa, curry, chutney and even wine but the most popular is, as with the Kiwi, to cut off the top and scoop out the fleshy inside with a spoon. The flavour is unusual and is described as a mixture of "strawberries and pineapple, with a pear-like gritty texture, and a hint of mint.’
This shrub has been mentioned in the blog once before but not for its fruit but for the exotic flowers see blog entry 29th June 2012 'Tomatoes and Pineapples'. When in flower or laden with fruit this rather ordinary shrub takes on a very different appearance and looks great against this south facing wall.  

Ripe Feijoa Fruit

Autumn Leaf Shape

Autumn Colour And Leaf Shape

Whilst many admire the autumn for its colour as the leaves change on the trees, the leaf fall also provides an opportunity to see the autumn from a different perspective. Predominantly seen as a colourful spectacle the many different leaf shapes that lay on the ground allow it to be seen from a different angle, above. As can be seen from the photograph there are many different shapes, from left to right around the top of the large palmate leaf in the centre, the Chinese horse chestnut (or Wilson's horse chestnut), Aesculus wilsonii, the leaves of the Catalpa, Plane, Sycamore, Liriodendron, Lime, Beech, Ginko and Hornbeam are a wonderful combination.

Chinese Horse Chestnut and Conkers

The Chinese horse chestnut not only has bigger leaves but it also has large chestnuts or conkers. As can be seen from the next two photographs below, the conker's size is compared for scale to a one pound coin, two pound coin and a group of three conkers from the European horse chestnut tree, Aesculus hippocastanum which is found all over Britain.

Conkers and Coins

Conkers, European Horse Chestnut Tree (L) Chinese Horse Chestnut (R)

Conkers On the Tree

The Chinese chestnut has a large, dark, single conker (seed) within a smooth, brown case rather than the 1-2 smaller, red-brown conkers in a spiky green case of the European horse chestnut. The young tree in the gardens has produced a dozen conkers this year but when it reaches its full height, 30 to 50ft, it should be full of giant conkers!

Chinese Horse Chestnut, Aesculus wilsonii

Giant Leaves

The Large Leaves On The Ground

The tree is not the only one in the gardens to produce very large leaves, the photograph below shows one of its leaves being compared to a leaf of the Chinese parasol tree, Firmiana simplex. Both giants amongst leaves they add their distinctive shape and size to this year's stunning autumn spectacle.

 Chinese Parasol Tree (L) Chinese Horse Chestnut (R)

For a comparison of the Chinese parasol leaves to other more common leaves see blog entry 10th December 2013 'The Giant Leaf Of The Chinese Parasol Tree'. 

Winter Protection For The Banana Plants

Top Of The Bananas

The day and night time temperatures are reducing and there have already been two mornings when the team have arrived at work to find frost on the ground. Usually found in tropical climates, the banana plants, Musa basjoo, in the herbaceous border, do not appreciate the colder temperatures and need to be protected from the frosts for the winter. 

Leaves Tied Around The Stem

 
However, five of the twelve banana plants are too tall to be easily wrapped so the decision was made to cut the top off to reduce their height, 5 metres were cut off on the tallest. Once reduced, and now with easy access using the smaller step ladder, the bananas are wrapped. Those still with leaves have them pulled down around the stem and tied to create a layer of protection. Those without their leaves, having had them cut off, are wrapped with a triple thickness of insulating horticultural fleece and those still with their with leaves, a double thickness. (The plants that had their tops removed had grown a few centimetres overnight before they could be fleeced, room has been left in the fleece for them to grow into!) When all are wrapped, a thick layer of leaf mould is added around the base to protect the root from frost. The plants will remain under cover until late May next year.

Grown A few Centimetres

Easy Access To Height

Wrapped And Mulched

Sugar Rush Purple, Blue Diamond and Ronaldo

Planted For The Summer, 9th June 2017

4th August 2017

4th August 2017

The pastel colours in the border at the far end of the quad have faded fast as the autumn progresses indicating to the team that it is time to change the display. 

Faded, 1st November 2017

Digging Out The Border

Cuttings were taken from many of the plants back in September and, apart from keeping a few as stock plants, the remainder are dug up and put on the compost heap. Before the border can be prepared for the winter planting the porous pipe has to be lifted, coiled up and put away in storage.

Porous Pipe Lifted and Coiled Up

Adding Leaf Mould

Once cleared of pipe the border is then weeded, the debris removed, leaf mould forked in and then the soil is levelled.

310 Wallflower 'Sugar Rush Purple'

Planting Wallflowers

With the border now ready, the 310 wallflowers are brought over from the nursery and placed out in to their position and planted. The chosen variety this year is 'Sugar Rush Purple', a large flowered, sweetly fragrant, purple wallflower that flowers before Christmas, in fact they have already started to flower!

250 Tulips 'Blue Diamond' and 'Ronaldo'

Bulbs Placed Out Ready For Planting

Once all the wallflowers were in the 250 tulips were placed out amongst them and planted. Two tulips have been chosen this year, Tulip 'Blue Diamond', a large double flower, bluish-purple in colour and Tulip 'Ronaldo', a single flower, dark purple-black in colour.

Finished!

Wallflowers and Bulbs