The first picture is of 2 Gardeners Delights, suffering from nutrient deficiency, leaves turning yellow in wan protest .

The next photo is the same 2 plants 10 days later, having got 2 helpings of Chempak up their xylem in the interim. I’ve didn’t remove any leaves – so it’s the same ones but gone green. Their improved condition has clearly also made them more delicious – I can spot Emmental style excavation in a couple of the bottom leaves.

An important purchase has been made; tomato feed. Which Magazine’s recommendation of Chempak’s Soluble Tomato food was out of stock so instead I picked up a box of Chempak, High Potash Feed. It’s referred to as No.4 (numbers seem much beloved by garden product suppliers; see John Innes) and described as the summer fertilizer for better blooms and bigger crops, especially tomatoes.

Packet Instructions

• Feed weekly from early stages. Increase frequency to twice a week when fruiting to improve quality and yield.
• Normal strength use: Dissolve 2 level measuresful of crystals in 5 litres of water and apply to your plants every 7 to 10days.
  Or
• For more frequent use: Experts prefer to use dilute feed more often. Dissolve 1 level measure in 10 litres of water and apply at every watering. At this strength this pack will make over 2,000 litres of plant food.

No guesses which approach I’m plumping for. Who wouldn’t want to self select expert! But in addition to fuelling my ego as well as feeding my plants, 2 other reasons weigh in behind this decision. First my watering can holds 10 litres so it’s easy to measure out (pathetic reason and worthy of instant ejection from expert category ) but more importantly this method is how West Dean manage their tomato feeding routine, dividing the weekly into daily doses. And if there is truly anyone who belongs in expert category when it comes to Tomatoes it’s the growers at West Dean.

The feed compromises 15+15+30 and trace elements. This translates as:

• 15% Nitrogen of which 8% is Nitric Acid, 2.8% Ammoniacal Nitrogen and 4.2% Ureic Nitrogen
• 15% Phosphorus Pentoxide
• 30% Potassium Oxide
• .1% Magnesium Oxide
• .006% Boron
• .013% Copper
• .025% Iron
• .013% Manganese
• .0003% Molybdenum
• .005% Zinc

I’d like to get hold of a pack of the tomato specific feed just to see how it differs.

800g of the soluble food cost £6.99 and if diluted to daily strength use will make over 2,000 litres of plant food which means filling the watering can 200 times over per packet …

To distract me from this Sisyphus syphonic task I turned to calculating how much watering each plant would require over a summer. My guide in this, Tomato guru, Terry Marshall. In his book ‘Tomatoes’ he quotes 100- 200 litres over the course of a full growing season.

This is weather and temperature dependent and as he grows tomatoes for 10 months of the year is 3 or more times longer than my growing season. But even so, it looks like I might need more than the one packet.

(Just one word of warning – when you open up the packet the product is of a blue hue. The sort of blue, scratchy bath salts were made of, the sort of blue that if it still has the temerity to colour up a  whole bathroom suite will invoke grand arm sweeping gestures from Kirsty and Phil house hunters accompanied by the utterance of the word replace.)

Last year I used Liquid Tomato feed. A few different makes including the one under which all others tend to be ‘Hoovered’ up – Tomorite. A bottle of Squires ( local garden centre) own-brand that’s hiding out under the sink has these instructions printed on the label:

• Growing Bags: From planting out, feed at weekly intervals. Increase the amount (product specific) after the 1st truss has set. And if the Grow bags are undercover, frequency is twice a week after the 2nd truss has set.
• Outdoor Tomatoes: Doesn’t specify when to start – but recommends every 2 weeks and then 1 x a week after 2nd truss has set.
• Under Cover (but presumably in borders not grow bags): After 1st truss has set 1x week.

I’m sure I can’t be the only tomato lover to  find it confusing !

However I also checked back on research done by Which? Magazine. 18 tomato feeds were tested on Growbags, planted up with 3 plants (Shirley) a piece.

No1 choice (which apart from Wilko’s was also the lowest , per feed,in price):

• Chempack Standard Tomato Food. A soluble as opposed to liquid food but clearly worth the extra step of dissolving the powder
• 2nd, but at the completely other end of the price scale, New Horizon Organic Tomato Feed
• Tomorite came within the top 6

The most compelling evidence of all…..what’s good for my tomatoes is good for the glutton within. No feed and the tomatoes produced a measly 4.5kg  per bag with a fruit diameter of 52mm whereas feed them with the best and they’ll laden themselves down with just over 13kg of fruit to a bag and need to let their tomatoey belts out a few more notches, to a diameter of 69mm.

Photo by fensterbme

Last week, in this Saturday Swot Shop series on soil, I got up close and mucky with manure.

This week I’m looking at fertilizers.  The difference:  whilst manures add nutrients to the soil, their most valuable role is to change and improve soil structure. Fertilizers play no role in soil structure; their role is to provide food/nutrients for the plant.

The two main things re fertilizers that I need to get to grips with:

• How to apply them
• How to choose the right one

Application is described by the mysterious terms –  Base Dressing and Top Dressing.

Base Dressing being when you incorporate fertilizer into the soil by forking or raking it in – before you plant anything.

Top Dressing being when you scatter or sprinkle the fertilizer around already planted individual plants .

There is also foliar feed. A method used with liquid products which involves spraying the feed directly onto the leaves of the plant.

And how to choose what I’m going to apply?  First decision:- Organic or Inorganic ?

Organic fertilizers come from decomposed animal or plant matter.
This gruesome menu includes bonemeal, hoof and horn, blood, fish and bone, seaweed meal, pelleted chicken manure, liquid comfrey or liquid seaweed.  Rather them than me!

Inorganic does mean artificial or manufactured products. However in the world of fertilizers it can also mean derived from natural sources but ones which don’t contain carbon i.e minerals or rock.

I then need to decide what form to get my fertilizer in.
Choices are likely to be powder, crystals, granules, pellets or liquid.

And then (often linked to form) I need to identify the rate at which I want the fertilizer to make itself available to the plant. Pot Noodle or slow roast ?

Quick Action gives an immediate but short term hit.
Steady Release works quickly and keeps releasing over the length of the season
Slow Release takes time to make itself available but once released is there for longer and so is more suited to permanent plants.

And final consideration, what’s in the nutrient nosh ?  The main three plant nutrients are nitrogen, phosphorus and potassium which always appear as NPK.

A straight fertilizer will contain just one of these three, a compound two or more and a general/balanced will contain all 3.

My final dig around in the soil will be next week.

Photo by Rob ‘n’ Rae

Week 12 started sunny and warm.  Hot enough perhaps to fool the tomato plants into thinking South America wasn’t so far away after all.  Tequila not Tomorite would still be their tipple of choice but all things considered, not too bad.  By the end of the week things weren’t looking so rosy and come Sunday morning , the thunder and downpour must have had them wondering how a pinata party could get so out of hand

But no casualties and all are now braving whatever the weather throws at them from their summer time pots or bags.

I think I might also have done a little cloud clearing of my own. If not please, put me right !  I can’t bear my confusion to continue.
It’s to do with feeding. The back of the tomato feed bottle reads  ‘ feed 3 weeks after planting or when the first truss has set ’, leaving me confused by advice to feed before that point .

Then the very slow penny dropped, clanged in fact !  The tomato feed bottle is referring specifically to that targeted product , a feed high in potash/potassium, essential to fruiting.  Before that need arises a general purpose feed could be used. Talk about feeling stupid ! 

As things would have it because my plants were put into pots or grow bags, they are in fresh compost which should contain nutrients for 4 to 6 weeks. But the cogs had barely stopped turning before I was in the car, in pursuit of all purpose feed.

Week 12 Summary.

Plants: All in pots or grow bags. The Tumblers which should be in hanging baskets are in taller pots which I hope have sufficient height for cascading down the sides.

Watering: I watered a couple of times at the beginning of the week and then the heavens took over; they were a little heavy handed.

Flowers: The Cream Sausage and the Darby Stripe continue to have flowers which come and go, with no sign of setting ! If, instead of hitting the road and tinkering with bikes, Robert Pirsig had stayed home to tend his garden he could still have written a timeless classic, only reworked as Zen and the Art of Tomato Growing.

Two Tumblers, one Moneymaker and the plant with no name in the blue pot now also have flowers. When it’s been dry and sunny I‘ve also been tapping away on their canes to aid pollination.

Feeding: None to date as no fruit set yet. But now I’ve been enlightened ..

And how are other tomato growers getting on ?

There’s an air and earth theme at Urban Veggie Garden Blog. Tomatoes are being grown direct in the soil in raised beds, supported by cages and also suspended upside down in mid air, supported by….?

Or if you’ve got the hang of cages and high wires then you might like to take a look at the Tormato.

If all this innovation above ground is too much then go underground and take a look at how to bury your tomato stem using the Sq. foot method as detailed over at Living the Local Life.

When we met Jim back in April we found out that Yorkshire tomatoes thrive on Sheep Soup ,  in Coastal Virginia they flourish on Geese Tea, brewed up in a paddling pool. Head over to My Island Garden for the exact recipe.

So much more exotic than General Purpose Food from a bottle!

How are your tomatoes coming along and what are they being fed ?

Saturday Swot Shop is for those things I should have been paying attention to years ago but didn’t.

Last Saturday it was Phosphorus/Phosphate .Today we’re still in the Lab to look at Potash/Potassium.
If you paid attention in Chemistry then you get to skip this. For me the only compounds I was interested in were practicing how my first name combined with the surname of my ‘crush of the week’. If you were similarly distracted way back when, then pull up a hard high stool and join me.

Potash and Potassium are they the same or different ?

• The same. Potash is the common name given to Potassium. Long ago Potash was obtained by burning wood or tree leaves, now it’s found by mining. It’s also why the chemical symbol for Potash/Potassium is K. It’s derived from the old word for potash, Kalium.

Enough history ! Let’s stick to chemistry. How does this relate to tomatoes?

• Potassium/Potash is 1 of the 3 main plant foods. Phosphorus and Nitrogen being the other 2. Potassium/Potash is important in the production of fruit. If the plant doesn’t get enough it will not produce many tomatoes and those it does, will be small and of poor quality.

So how do I make sure my tomatoes get enough ?

• That’s what specialist tomato feeds are for. They contain the other 2 nutrients but a higher amount of potassium/potash. On the back of a tomato feed bottle look for ‘Potassium Oxide (K20) soluble in water 8.0% w/w (6.6%K)’. You will also see Compound Fluid Fertiliser (5.3, 2.7, 8.0), the ratios of each nutrient. In a general fertilizer they would be roughly equal.

Makes so much more sense this time around !

Photo by Chemical Heritage Foundation

There’s a lot of P when it comes to tomatoes.

• P ?

Phosphorus, Potassium, Potash, Phosphate etc.

• If it helps, Phosphorus and Phosphate are connected as are Potassium and Potash.

And what’s their ppppurpose ?

• Phosphorus and Potassium are 2 of the 3 main foods plants need, the 3rd being Nitrogen. Each has a specific function relating to the healthy growth of the plant.

Phosphorus. Doesn’t that make things glow in the dark ?

• A plant uses Phosphorus for root growth. A lack of it will lead to poor root growth. As for glowing in the dark, perhaps your pots light up at night !

And what is Phosphorus to Phosphate ?

• In terms of plants and root growth think of the words as interchangeable. In terms of the actual difference , I think Phosphorus is the element and phosphate is the salt (obtained by mining) that contains that element. Oh and the symbol for Phosphorus that’s…..P.
  And of course the tomato was known as the Pomme d’Amour.

Thank you! Enough Ps for one day !

If  you paid more attention in chemistry please feel free to chip in, if that’s not right !

Photo By sun_rise_light_flies