Heirloom?

Peter . A lady was talking about heritage tomatoes and I will tell you where to buy them. She has not answered my emails. Can you tell me, I think she was talking about a nursery the western side of melbourne. Laurie
Truth is I have no idea Laurie, but it’s enough to encourage some thoughts on what an heirloom is.
Our sales rep Di has been nagging me about the labels we use on our Tomato seedlings. “They have to have the word Heirloom on them. I don’t care where; it just has to say Heirloom”. Now, I tend to be a little pedantic and the idea of just printing Heirloom worries me. I used to believe that virtually any Open Pollinated plant that had been around for more than 30 years could be described as an Heirloom variety. Now I’m not so confident.
Let’s start with the term Open Pollinated. The nursery trade fairly casually divides plant varieties into 2 categories: OP’s (Open Pollinated varieties) and Hybrids. I’m already getting worried that this newsletter might get too technical so for the sake of simplicity let assume that OP’s are older and cheaper and the Hybrids are new and generally more expensive. Another way to look at is to assume that OP’s are naturally pollinated by bees and Hybrids have endured some human intervention.
Anyone that has grown their own Tomatoes in Victoria will know the classic OP Tomato varieties: Grosse Lisse, Roma, Rouge de Marmande. Most of us are familiar with some very successful hybrid varieties too: Mighty Red (Carmelo), Apollo and Sweet Bite. Recently however the developing interest in culinary gardening has ignited interest in what used to be the preserve of a select group of enthusiasts: Tomatoes with fascinating flavours, colours, textures and sizes. The Heirloom varieties.
When I wrote about the origins of modern Tomatoes a few weeks back, I gave a good deal of credit to European and North American Tomato breeders for developing the large and luscious fruit we know. What was involved in this process? Not much more than a passion for observation and selection of seed from the plants the performed the best, not much different to the Incas and Mayans who had started the process centuries before. To the purist, Heirloom vegetables are those varieties selected by gardeners for their own use and shared with their families and friends (sounds like Cannabis doesn’t it?). That’s it! Convoluted perhaps, but really quite simple. Of course one of the great things about Heirloom varieties is they come with terrific stories: Radiator Charlie paying off his mortgage, the mysterious Cherokee Indians (see image with thanks to Tomatofest) supplying seed to American frontiersmen and the eccentric breeder of ‘modern heirloom’ varieties like Green Zebra, Tom Wagner. If you are really keen follow the link to Tom’s blog, it’s fascinating but pretty technical.
So where do the Classic Varieties like Grosse Lisse fit in? I’ll look at those next week.

Burnley Pruning Day

Here's a great chance to get genuine professional tips on pruning your garden and all sort of other information and advice.
The Burnley Pruning Day is on again, Saturday 18the July, at the historic Burnley Gardens, Swan Street Burnley.
Follow this link for all the proper details. I'll be there, love to see you.

Frost

“Would like to know what can we do to protect plants from frost? I heard there is a spray for leaves, but i've had no luck finding it yet. Is there such a thing?
Thanks for any info.
Best Regards, Patricia”

I recall mornings where the water froze in the nursery pipes but I’m sure we haven’t seen the like in the past 15 years. It can however still get very cold some mornings, cold enough to damage some of our favourite plants. Melbourne is a pretty safe horticultural environment when it comes to frosty mornings but there are definitely parts of Victoria that frost can be a real issue.
Frost is a weather event like extreme heat or hail. We deal with it relatively rarely say two or tree times each season, but we spend an enormous amount of energy and effort preparing ourselves for these few events. At this time of year we watch out for high pressure systems and those beautiful clear evenings when the temperature drops suddenly, it’s a fair guess that we are in for a cold night. It is important to understand that frost is not cold air, cold dry air just helps produce the frozen frost crystals. It is also important to remember that the very cold air that produces old Jack Frost is heavier than other air so it pools in low, sheltered places, not on hill tops or slopes.
So what do we do to protect our plants from Frost? Well let’s start by not growing plants that are severely damaged or by growing them in a protected environment. I have never forgotten the heartbreak of having been forced to move Tomatoes and Marigolds outside early one October because we had completely run out of protected space. October! We had the lightest of frosts but it was enough to turn all of those beautiful plants to a very ugly, black, melted plastic constituency.
Protection is the other critical frost protection factor. A shade cloth cover can be all that is needed. We have when desperate, risked the physical damage of simply laying spare pieces of shade cloth (Hessian or a sheet would work perfectly well) directly on exposed plants. Of course we have green houses and shade houses for protecting plants. Shade from trees is just as effective as is the eve of a building or the radiated heat absorbed by a north facing wall.
If physical protection from frost is not available, water can be very valuable. My understanding is that the “burning’ symptom we see is the result of the plants cells having been frozen. When the cells of frost sensitive plants are frozen they collapse and die. This of course happens in the coldest hour before dawn. Applying water can have a number of effects. Primarily the water is warmer than the freezing air. This of course can change pretty quickly but the theory is that water actually releases a little heat as it converts to ice but this is of little value in our situation.
The other advantage of watering on frosty mornings is that the activity actually stirs up the cold air, mixing it with marginally warmer air. This is a theory used commercially where large fans, even helicopters are used to circulate air over crops on frosty mornings. Ok so this is probably not feasible at home.
There are chemical solutions to the frost problem that are used quite widely in the nursery industry so I assume they are reasonably effective. Copper based sprays like Bordeaux mixture are believed to strengthen plant cells, protecting them from frost damage. Yates produces DroughtShield which is widely available in good garden centres and is apparently quite effective. Envy is the most commonly used product in the trade but I am not sure if it is available in home garden packages.