tomatoes on hot Sardinian Terrace

[botanikk]

I'm not sure what the calcium situation of my water is here, I guess I could check with my neighbors. As for the spraying, I do it to keep the spider mites away. In this hot, dry climate, they will destroy your garden otherwise. However, since they highly dislike moisture, I don't have problems anymore because they don't even come to my terrace. Do tomatoes have some issue with being sprayed? I haven't noticed any problems with other plants. I would imagine the plants benefit from the "humid" nights I create. Keep in mind that humidity here on a summer day can be 15% and perhaps lower.

[troad]

Aaron,
The usual directions I,ve read on tomatoes is not to water late in the day. Also in watering try not to splash possible soil contaminants on the plants when you water them. By watering early in the day the tomatoes have time to sun dry before night time. Obviously you have plenty of sunshine.
I was just trying to pose a possible area of potential problem. You do not say what your growing medium is nor wether the locals healthy plants are staked or allowed to sprawl. Tomatoes are very strong plants but are susceptible to fungal and viral pathogens. Could there be contaminents in the soil or airborne spores etc ? Are you using potted soil or? What do the local people do as far as watering?
Suze and Dice are on target and have a lot more experience than I do. Just trying to get a little better picture of your problem. Maybe if I ask the right question some one here can better help you.

[dice]

What Troad is thinking of is fungal leaf disease, which
benefits from a moist environment. Here in N. America,
we are often struggling to keep the leaves dry enough
to inhibit the onset of Early Blight or Late Blight, and
we go to great lengths to avoid splashing spores from
the soil up onto the leaves and stem of the plant.

(That is why you see a lot of mention of Daconil in threads
here and there. It contains an anti-fungal compound that
seals off sites that fungi bind to on a leaf or stem.)

If we spray tomato plants (anti-fungal, pyrethrums,
garlic-and-cayenne, foliar feeding, whatever), it is
done early in the morning on a hot day, so that the plant
dries off quickly, and hopefully not on a windy day.

Brief BER fact sheet:
http://ohioline.osu.edu/hyg-fact/3000/3117.html

(Note that the "inches of water per week" in that page
probably varies in the real world with the exact kind of soil
and weather that you have.)

Some other calcium sources besides lime: gypsum (that
is what drywall is made from; used when you have near
neutral soil already and don't want to shift the pH upward);
crushed (ground if possible) eggshells; chipped oyster shell;
bone meal; fish bone meal; crushed crab shells; synthetic
calcium carbonates like SuperSweet (fast breakdown);
wood ash (fast breakdown, can radically shift pH upward); comfrey leaf; vitamins (this is a fairly expensive calcium
source).

[botanikk]

fungal diseases on leaves are not a problem here (in the summer), watering at night or not. Any suggestions for varieties that might do well in containers in a hot climate? Might be better to try some kinds that set fruit better in warm weather. I already have olpaka and black krim.

[botanikk]

I think a mulch will help a lot. Thanks Dice for the link. I think a mulch, some afternoon shade, larger containers, choosing varieties carefully and perhaps a bit of calcium should do the trick. Should 10 gallons each be ok? what about cherries? I take it they need less? I also guess that indeterminate are better (not to mention more useful).

[dice]

Should 10 gallons each be ok? what about cherries?
I take it they need less? I also guess that indeterminate are
better (not to mention more useful).

For some compact cultivars, 10 gallons is ok. It depends more
on the size of the plant (leaf surface area) than on the size
of the fruit. Growing in the ground, most tomato plants, both
determinates and indeterminates, can easily fill a 3'x3'x3'
space with roots.

What you find growing in containers is the need to water
daily, sometimes twice a day, in hot weather (which you
have an abundance of there in Sardinia). A moisture meter
would probably be a big help here, so you can get an idea
of how fast the containers are drying out.

"Will grow well in a container" and "does well in the heat"
are not necessarily going to be the same cultivar. These
do better than most in the heat: Eva Purple Ball, Mule Team,
Arkansas Traveler (or Traveler or Traveler 76), Carmello (or
Crimson Carmello, a French Hybrid, should be available
locally there), Rio Grande (determinate paste), Principe
Borghese (indeterminate cherry), Stupice. There are doubtless
others, but those are the ones that I have heard "kept setting
fruit in the heat of midsummer" comments about from people
that live in climates as hot as yours. All but one are
indeterminates and can get big.

What you will probably find is that the size of the plant
ends up limited by the size of the container (meaning that
any of them will be modest-sized growing in a 10-gallon
container compared to how big they would get growing
in the ground in the same climate).

If you are looking at commercial hybrids recommended
for hot climates, look for "semi-determinate". Those will stay
more compact than most indeterminates yet produce fruit over
a longer season (usually) than determinates. Some of them
behave like a 2-crop determinate, where you get a concentrated
set of a lot of fruit all at once, more or less, then after you
harvest them the plant keeps growing and produces another
set that also ripen at almost the same time.

Another one to try is Russian Red. It was not bred for the heat,
specifically, but it is known as a tough plant that can take
a lot of abuse and still keep producing. As a rugose-leaved tree-type dwarf (stubby growth habit, thick stems), it should
take longer to outgrow your containers than regular
determinates, semi-determinates, and indeterminates.

So what are the local farmers growing? How do they taste?

You are probably close to the water. What about scrounging
around down there for shells, fish skeletons, kelp from nets,
stuff like that? In a location like that, you should be able to
add marine sources of calcium and other goodies to your container mix practically for free.

[botanikk]

Thanks Dice. I guess that perhaps better than a certain variety that might do well in the heat, it would be better to choose one that doesn't get very big. Based on the description, it seems that HuskY Cherry Red might be a good idea. it's pretty dwarf and fruits all season long. I could check local varieties as well, but like I said, I've seen fields of tomatoes growing fine in the dry summer heat, with lost of fruit. I think the issues are more about growing in containers, where keeping them watered is a problem, and the terrace is ovbiously hotter than the ground. With all the advice I've gotten, I think I'll be ready to try this year, even with the kinds I already have.

[mdvpc]

I live in the desert southwest, where its hot and dry all summer. I grow only in containers. If you do a search here for my posts, you can see some of the varieties I grow. There are lots of them you could grow, but the timing of putting your plants out is very important. If you want, take a look at some of my threads/posts and let me know if I can help you out with some seed. TGS has some hybrids that set well in the kind of heat we have-I have grown them. I am not a fan of hybrids, but this summer I am going to have 6 plants of two of them to trial them again. When you have sustained heat of 95-100 during the day, and 75 as a low, blossom drop is inevitable.

[bcday]

One thing that works for me in addition to mulch is shading the sides of the container by setting it inside a larger container or a planter box so there is a little empty space between the two. Or you can put something decorative next to the containers on the south and west side to shade just the root zone rather than the whole plant. It's surprising how hot the sides of the container will get in the sun, especially when sitting on a paved surface. With shade from the side and mulch on top, the plant roots are less overheated and the soil loses less moisture to evaporation while staying more evenly moist between waterings.

[mdvpc]

I use white containers and zeba.

[dice]

A couple more good hot-weather cultivars: Jetsetter, Creole.

Skyfire sells a mix of cultivars that have done better than
most in mid-summer heat in Kansas (it says 25-30 seeds,
and I don't know whether they are sorted by cultivar).
Their catalog also has notes on how individual cultivars
that they sell seeds for did in the heat:

http://skyfiregardenseeds.com/#Tomatoes

Beyond a certain air temperature, that varies with cultivar,
there just is not a lot you can do, because pollen becomes unfertile (and to some extent ova in the flowers, too). One
trick is to go around early in the morning, before it heats
up, and shake the plants. Some flowers will get fertilized
by pollen that developed the night before and has not
been exposed to the heat of day yet.

[amideutch]

Aaron, looks like all of Tville has come to your aid. Definately check out mdvpc's prior posts as he is one of our container guru's while doing it in the heat as well. And he can definately fix you up with a few good varieties so shoot him a PM and take him up on his offer. Planting time down in your area will be comming up shortly. Ami

[botanikk]

I currently have seeds of Legend, Gold Nugget, Juliet, Olpaka, Pink Brandywine, Black krim, Mariana's peace, and some beefsteak (the variety I don't know). Which or these would you recommend or advise against trying? I already have 2 Gold Nuggets growing, but I'd rather wait to see what people advise before planting others. I was thinking of ordering a few varieties from TGS, but I'll wait for advice first. Thanks for the posts everyone.

[mdvpc]

Ami-thanks for the compliment. Aaron, Pink Brandywine (which is really just called Brandywine) and M. Peace will be difficult for you. The cherries will be fine. Opalka, you may have ber problems. If you want a paste, Heidi may be a good choice-its from Africa. Black Krim may do ok-I grow black varieties and one year they are good and another they arent.

[dice]

Here is a thread to keep an eye on:

http://www.tomatoville.com/showthread.php?t=7652