Disease (Farming)

Disease is a condition that can afflict most crops grown through the Farming skill. When a healthy crop ends a growth cycle, there is a chance it may become diseased. While diseased, the crop stops growing and does not advance to the next stage. Crops do not recover from disease on their own, and may die at the end of the diseased cycle if left uncured. The cycle length of a diseased crop will tend to become one tier slower than if it were healthy, using the next slowest growth tick than typical for the crop.^[1] Dead crops yield no experience and require use of a spade to dig up their remains before planting another crop in the patch.

Players may treat plants in diseased herb, flower, allotment, hops, hardwood tree, celastrus, belladonna, cactus, and mushroom patches with plant cure to restore the crop to health. Doing so may let the crop advance to the next growth stage normally upon the end of the cycle, although it is possible that it may become diseased again. For diseased trees, fruit trees, spirit trees and bushes, the player may use secateurs on the plant to trim the diseased branch and restore the crop to health. Alternatively, if a player has access to the Lunar Magic spellbook they may use the Cure Plant spell instead, which saves the player valuable inventory space during Farming runs.

Players may purchase plant cure from a Farming shop, but it is usually both more convenient and less expensive to purchase it from the nearest farmer.

When using secateurs, there is a 75% chance to successfully prune the tree or bush, resulting in the message You have successfully removed all the diseased leaves. The other 25% of the time players will receive the message There are still some diseased leaves left. and simply need to try again until they succeed. The amount of time it takes to attempt to prune the plant is randomized, and on average decreases with Farming level.^[2]

Crops grow in real-time, so they may become diseased when a player is offline. In addition, crops that have been cured of disease may become afflicted once again. Crops cannot become diseased in the first growth stage (i.e. immediately after the seed has been planted), and fully grown crops will not become diseased.

An amulet of nature alerts a player to disease if worn, and may also be rubbed to check whether or not a plant is still healthy.

Each crop type has a predetermined probability of becoming diseased each crop window. Treating a farming patch with compost, supercompost or ultracompost before (or immediately after) planting a crop reduces the chance of disease during all growth cycles by 50%, 80% or 90%, respectively, rounded down to the nearest 1/128th. If an Iasor is planted and alive, disease risk of all crops is reduced by a further 80%,^[3] to a minimum chance of 1/128 per growth cycle. The risk of a plant becoming diseased without any treatment varies depending on the crop (and potentially the specific patch, or even the individual growth stage).^[4] These rates are unknown, except for the following crops:^[5]

The probability a crop will fully grow without getting diseased and dying is , where is the probability found in the above table and is the number of growth cycles where the crop may become diseased. For example, fruit trees can become diseased in 4 of their 6 growth cycles, so if ultracompost is used the tree has a chance of fully growing without becoming diseased and dying.

If a player forgets to treat a farming patch, the expensive but useful Fertile Soil spell may be used to treat the patch with supercompost (or ultracompost if you have previously read the Ash covered tome) both before and after planting a seed or sapling. Supercompost and ultracompost can also be used before or after.

Watering allotment, flower, and hops patches with a watering can reduces the risk of disease occurring at the end of that growth cycle.^[6] During the next growth cycle, the plant changes from being watered back to normal and has a higher risk for disease once more, unless it is watered again. Only allotment, flower, and hops patches may be watered.

Planting different flowers or a scarecrow provides protection from disease to a variety of crops in allotment patches once the flower is fully grown.

The special herb patches unlocked by completing My Arm's Big Adventure and Making Friends with My Arm are immune to disease, although herb yields may still be increased by treating the patches with super/ultracompost.

With the easy tier of the Kourend & Kebos Diary complete, the allotment, herb, and flower patches in Hosidius will no longer become diseased.

With Champion status in the Fortis Colosseum, requiring 16,000 Glory, the herb patch west of Civitas illa Fortis will no longer become diseased.

With the elite tier of the Falador Diary complete, the tree patch in Falador Park will no longer become diseased.

With the elite tier of the Morytania Diary complete, you get access to a disease free herb patch on Harmony Island.

Otherwise, the only way to eliminate disease risk entirely from all other patches is to pay one of the farmers near the farming patch to watch over it and ensure that it grows to completion. Payment must be in the exact form requested. For instance, a farmer does not accept 5 apples in lieu of a basket of apples. However, farmers do accept noted payment, therefore a noted basket of apples would be accepted. Note that farmers require separate payment for each allotment patch.

The belladonna and mushroom patches do not have farmers available to oversee them, however. While farmers can oversee allotment patches, they cannot prevent the nearby herb or flower patches from becoming diseased.

Poison ivy bushes are immune to disease. Farmers will not accept payment to watch over a poison ivy bush.