Sunday, July 13, 2014

Maximising your Strawberry Crop

July is the perfect time to create a new strawberry patch or give your strawberry plants their once-a-year haircut and do other things to maximise your crop in the new season.



My strawberry patch is in a corrugated iron raised bed (easy on my back) in a spot where it gets sun all day except first thing in the morning.  My strawberry plants produce their first ripe strawberries mid November and keep producing until early May.  However, that only happens if plants are prepared really well for the season ahead.  This is best done in June - August when plants are dormant.

My preparations for the next strawberry season started today, and this is the mess I took a picture of when I was halfway:

Done the front bit, but there is lots more to do

I removed old and dead leaves, runners and old fruit from each plant and potted up runners that during the season had taken root outside my raised rows.

This was the result an hour or so later:

The once-a-year haircut is complete and now I am ready to replace plants and fertilise

But let's start at the beginning: what to do if you want to start a brand new strawberry patch?

As a child in the Netherlands I remember finding tiny strawberries on wild strawberry plants in the woods.  For a long time my perception of growing strawberries was that they were care-free plants that needed little attention.  I was wrong.

Modern strawberry varieties need sun and constantly moist but not too wet soil with lots of readily accessible food.  In the photo above plants are planted in rows on ridges to make sure that the soil surrounding the roots is never too wet.  Strawberries like good quality somewhat acid soil (a pH of around 6 is great), that is not too sandy and not too clayey.  They don't like competition from weeds, hence my use of weed mat.  Modern strawberry varieties are fussy!

If you start from scratch select an area that gets all day sun with good quality not-too-heavy soil. 

Add a good quantity of well matured compost, if you have any, and mix it all in.

Don't add gypsum, lime or dolomite.  Modern strawberry have forefathers who grew in forests and inherited from them a desire for acid soil.

Realise that your strawberries will occupy this area for a number of years.  When you create a new patch is the time to give them the best you have because you won't be able to improve the soil structure much once your plants are in place.

Next form ridges and gullies.  25 centimetres between the tops of the ridges is fine.

This 2.4 m long x 1.4 m wide corrugated iron raised bed means no back-breaking work 

Now cover the area with weed mat and cut holes in it to plant your strawberry runners (around 25 - 30 centimetres between plants in the rows).

Initially you may need to lay some old bricks or garden stakes in the gullies to make sure the weed mat does not blow away in the first storm.

No need to cover your strawberry patch with netting just yet, but as soon as the first strawberry goes red in October, you will have to.  An easy solution is a poly pipe structure with bird netting:

Make it so the net is easy to move on and off and does not blow away

In the old days straw was used around strawberries to make sure berries were never resting on the ground and rotting.  If you plant your runners on ridges and use weed mat, mulch is not essential, but pine needles or straw might help to retain moisture.

June - July is the best time to buy strawberry seedlings, called runners. A bunch of ten runners with a bit of soil in a pot should cost around $1 per runner.  If you buy young strawberry plants later in the season, they will only be available one per pot and may cost around $5 per plant.

In Tasmania the most common varieties are Red Gauntlet and Tioga, probably because they are both suited to cool climates.  Red Gauntlet is a robust long-season prolific producer of medium size fruit and for this reason it is favoured by many commercial growers.  Its strawberries are not as sweet as some other varieties.  Tioga starts to produce a bit later, but fruit is larger and sweeter.  With strawberries, like with most fruit, it is not a matter of the sweeter the better.  I recommend you combine both varieties in the one strawberry patch, so you get fruit over a longer period of time. 

Less common varieties are also worth incorporating in your patch. They might fruit earlier or later or produce larger or tastier fruit.  The less common varieties may be dearer to buy.  Whatever varieties you buy, fruit will be fresher and tastier than anything you buy in punnets in shops.

A runner ...... running too fast

If, right now in winter, your new strawberry runners look as cute as in the photo above you need to be tough and remove all flowers and fruit.  This plant needs to take root and form leaves before it spends any time on flowers and forming fruit.  You will get a much longer lasting and productive plant if you allow them to establish themselves before getting into all this over-early fruiting nonsense.

Here is one of my one-year-old plants after its haircut:

A one year old plant ready for the next season

It is recommended that you replace strawberry plants after three seasons.  

In my patch most plants are replaced earlier than that.  I decide which ones to replace after their once-a-year haircut when I see how vibrant or half-dead or dead a plant is.

It is not a good idea to have strawberries in the same soil for many years.  In Tasmania's relatively cool conditions strawberries are subject to few diseases, but it is still recommended that you move your patch to another spot or, in my raised bed, remove the top layer of soil and replace it with new fresh soil  every 3 years.

When planting a young strawberry runner position the point where the leaves come together, at or just above ground level.  As plants mature they seem to often push themselves up out of the ground (see the photo above), but that does not matter.  Do not add soil around those plants or push them back into the ground.

Now, the last thing I need to do, and then the plant is ready for another season, is to give it a nice handful of blood and bone, under the weed mat, all around the plant, work that in with my hand and water it in.  This is another reason why I do my strawberry maintenance now, in July.  By the time the blood and bone has been converted and is ready for the plant to access it will be October, just when, in Tasmania, strawberry plants need to begin to think about forming flowers.

With the haircut done and blood and bone added, I leave my strawberry patch alone for a while, except that, in my garden any flowers, let alone fruit, that form before the end of September, are ruthlessly removed, because temperatures are most likely too low to give these early forays into fruiting a chance and they take energy away from forming good roots and leaves.  Any weeds that appear in spite of the weed mat should also be removed immediately.

By mid October temperatures should be high enough for fruit to have a chance to ripen successfully.

Strawberry plants root shallowly.  This means that, at any time of the year, if you allow the soil to dry out, plants might suffer or die. 

By late October it is time to net your strawberry patch and monitor soil moisture closely because plants will want constant moist but not too wet soil from here on until the end of April. 

I hand water around plants and in gullies between rows, making sure that excess water always has a chance to get away. Alternatively you could of course install drip irrigation. If you water too much on the fruit you may find that your fruit will begin to rot.

In the first year in new soil you may find that plants form many leaves and not a lot of fruit.  This happens if your new soil has too much nitrogen.  To encourage fruiting remove some of the leaves and all runners and mix in with the soil around each plant some sulphate of potash and water that in.

The result of good care will hopefully be something like this ...

Red Gauntlet is prolific with mostly medium size fruit

During the fruiting season I remove most runners because they distract plants from focusing on fruit, but I don't remove all of them to give myself a nice quantity of new runners for the following season. Once a healthy runner that will be useful next season is established you can cut its tie to its parent plant.

Runners just potted up

The runners in the photo above took root through the weed mat in the gullies where I don't want them.  I put them in pots as I gave plants their haircut and when they perk up I will use them to replace half-dead and dead older plants.  If I have too many I will take them to the produce table at one of our food garden visits!

In my garden, if during the season I keep soil conditions moist, but not wet, and occasionally foliar feed with seaweed extract when plants stop flowering, I have ripe strawberries from mid November until early May.

Strawberries are a very rewarding crop that can give you plenty of fresh fruit and wonderful jam.  Potting up runners and nurturing them into productive plants is a great way of introducing children to food gardening.



2 comments:

  1. What a great article - makes it easy to follow. Can you just tell me though how to do the blood and bone bit under the weed mat - if the plants are already in, it would be hard to get under the weed mat wouldn't it?

    ReplyDelete
  2. Thanks Petal! The weed mat should never be so tight around plants that you can't lift it up and put a few fingers in to guide the blood and bone down onto the soil. If it is too tight, just cut it a bit, until you can. (reply by Max Bee)

    ReplyDelete

Note: Only a member of this blog may post a comment.