Sheri,
BASIL
First, about the basil, since the answer is short and sweet.
You can harvest basil leaves anytime you want once the plants are a few inches tall.
It is best to harvest before the plants go to seed as the leaves will have the best flavor then. You can harvest leaves on an "as needed" basis, or you can harvest a lot at one time, and hang the leaves to dry. Some people make lots of pesto at one time when they have a lot of basil leaves, and freeze it for future use.
I cut off any flower stalks that appear on my plants in order to encourage the plants to put their energy into leaf production instead of flower/seed production. Once the plants start flowering, you can still cut them back just a few inches from the ground and they will put out new foliage. This gives you a longer harvest period.
TOMATOES
I don't know of much of anything you can spray directly on the fruit to deter pests, at least not anything that I would ever spray on food I was going to eat. Your best bet might be a non-toxic kaolin clay product called Surround. It coats the plant or fruit, depending on how you spray it, with a light coating of clay that makes the fruit or veggie less appealing to pests. Once you harvest the fruit, you wash off the clay. I have never tried it, but some people have been happy with the results, esp. on fruit trees.
I've linked some Surround info below. When it first came out on the market, you had to mail order it or order it online to get it. However, for the past couple of years, I have seen it in some full-service nurseries that have a good selection of organic products.
The yellowing of the leaves probably is early blight (Alternaria solani). Early blight is a common fungal disease and it is found worldwide, so if you grow tomatoes it will show up at some point, although often it does not show up the first year in a new garden. It always shows up at about this time of year, especially in years when we have lots of rain and higher than average humidity. In general, it will progress up the plant and completely defoliate it, causing the death of the plant. There are some tomato plants that grow vigorously enough to releaf and 'outgrow' the early blight, but they tend to be the exception rather than the rule.
Early blight usually shows up first on older leaves as irregularly-shaped, brown necrotic lesions which expand as the disease progresses. Eventually they will often develop concentric black rings that remind one of a target. The yellow areas begin to surround the dark lesions, and the entire leaf may turn yellow as the disease progresses. Once the entire leaf is yellow, it is going to dry up and die.
To a lesser extent you may notice brown, elongated lesions on leaf stems and petioles. As the disease progresses even further, you may see fruit lesions near the calyx end. These lesions are dark brown to black, have a sort of leathery look to them, and often appear to be somewhat sunken in. They usually develop that concentric target appearance too.
Some of the tomatoes that I have grown which have been able to outgrow early blight include Better Boy, Brandy Boy, Nebraska Wedding, Cherokee Purple (some years), Sweet Million, Ildi, Sungold, Persimmon, Black Krim (some years), Aunt Ginny's Purple, Mortgage Lifter, Black Cherry, Black Prince, Whopper and Viva Italia.
Some years the early blight is more mild, although it is definitely there. Other years it is just awful. Early Blight is, in general, the reason that fresh fall plantings are a good (great!) idea. Some tomato plants do survive early blight, but they use up all their energy fighting to survive, and produce a poor crop as a consequence.
Their is no 'cure' for early blight once you have it. The best way to fight early blight is to try to prevent it. Some people spray their plants at regular intervals with a fungicide like Daconil that is labeled for early blight. Others try to prevent it organically by using Serenade, a copper-based fungicide, or baking soda sprays.
Early blight generally survives from season to season on decayed plant material in the soil. It is not just a tomato disease, affecting other wild and cultivated members of the solanacea family. If your garden space allows, a three to four year rotation can help keep early blight at a manageable level.
In a dry year, you can minimize early blight by keeping water off the foliage as much as possible. This includes only watering with soaker hoses or drip irrigation and keeping all moisture off the foliage. Mulching all areas of the garden, including pathways, helps also as it reduces soil splash. Of course, in a year like we have had in 2007, the rain, heavy dews and high humidity make it impossible to keep moisture off the foliage.
Yellowing leaves are not caused solely by early blight, or course, and yellowing leaves on tomato plants have many causes. However, in our climate, early blight is very often the cause of the yellowing leaves. I always remove blight infested leaves, and I don't like to spray anything on food we are going to eat, so I don't use chemical fungicides like Daconil. Thus, I always have early blight and always just plan to replace my spring-planted tomatoes with new ones for fall as the need arises.
Bacterial speck and bacterial spot are both common in rainy years too as they develop under the same type of weather conditions that are favorable for early blight. Often I see bacterial speck and spot diseases prior to early blight. Copper-based fungicides help keep them under control to a certain degree. However, in a year like this where we have had six to eight to ten days in a row with rain falling, it is hard for any of the foliar sprays to be really effective.
Most years, Early Blight begins to rampage through the plants at about the time they are covered in green tomatoes that are just beginning to ripen. You can usually keep the plants alive a month or two longer, or at least long enough to harvest most of the fruit as it ripens. It is rare, though, to get the average plant with early blight through the entire summer. Even those plants that survive early blight are so stressed that the spider mites tend to attack them quite vigorously, since spider mites are attracted to stressed plants.
I don't usually have an early blight problem on fall tomatoes. By the time the fall tomatoes are in the ground, the rain has stopped (most years) and the plants don't have much if any moisture getting on their leaves. Of course, the way things have gone this year, it is possible we will continue to have rainfall all summer and will have to deal with early blight on the fall tomatoes too.
Early Blight is one of the main reasons that it is so much easier to get a good crop of tomatoes in drought-type conditions and it is so much harder to get a good crop of tomatoes in rainy conditions. That seems backwards, I know, but it is what it is.
I hope you get a good crop before the early blight wins the war.
Dawn
Here is a link that might be useful: Surround At Home Information
sheri_nwok
Okiedawn OK Zone 7Original Author
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