I'm currently in the process of creating my first mod that will add some new chemicals, plants and drugs made from them (started with following the Euphorium tutorial), and there is a harvest button missing from the plant. I looked closely at game default xml files for other plants and simply can't figure out what exact "def" is responsible for it. The xml for the plant is down here.
<?xml version="1.0"?>
-<Defs>
-<ThingDef ParentName="PlantBase">
<thingClass>Plant</thingClass>
<defName>VeilPlant</defName>
<label>veil plant</label>
<description>description</description>
-<graphicData>
<texPath>Things/Plant/VeilPlant</texPath>
<graphicClass>Graphic_Random</graphicClass>
-<shadowData>
<volume>(0.15, 0.3, 0.15)</volume>
<offset>(0,0,-0.38)</offset>
</shadowData>
</graphicData>
<blockWind>false</blockWind>
<selectable>true</selectable>
-<statBases>
<Beauty>2</Beauty>
<Nutrition>1.5</Nutrition>
</statBases>
<altitudeLayer>Building</altitudeLayer>
<ingestible/>
<passability>PassThroughOnly</passability>
-<plant>
<soundHarvesting>Harvest_Standard</soundHarvesting>
<harvestMinGrowth>0.90</harvestMinGrowth>
<harvestAfterGrowth>0.40</harvestAfterGrowth>
<dieIfLeafless>true</dieIfLeafless>
<growDays>2</growDays>
<visualSizeRange>0.3~2.0</visualSizeRange>
<sowMinSkill>10</sowMinSkill>
-<sowTags>
<li>Ground</li>
</sowTags>
-<sowResearchPrerequisites Inherit="False">
<li>VeilPlantsSowing</li>
</sowResearchPrerequisites>
<topWindExposure>0.15</topWindExposure>
<mustBeWildToSow>false</mustBeWildToSow>
<treeLoversCareIfChopped>false</treeLoversCareIfChopped>
<interferesWithRoof>false</interferesWithRoof>
<blockAdjacentSow>True</blockAdjacentSow>
<immatureGraphicPath>Things/Plant/VeilPlant_Immature</immatureGraphicPath>
<harvestWork>100</harvestWork>
<harvestTag>Standart</harvestTag>
<harvestYield>20</harvestYield>
<harvestedThingDef>VeilLeaves</harvestedThingDef>
<harvestFailable>true</harvestFailable>
<wildOrder>2</wildOrder>
</plant>
<tickerType>Normal</tickerType>
-<comps>
-<li Class="CompProperties_SpawnSubplant">
<compClass>CompSpawnSubplantDuration</compClass>
<subplant>VeilPlantRoots</subplant>
<maxRadius>1.9</maxRadius>
<maxPlants>8</maxPlants>
<subplantSpawnDays>1</subplantSpawnDays>
<minGrowthForSpawn>0.4</minGrowthForSpawn>
<initialGrowthRange>0.1~0.1</initialGrowthRange>
<canSpawnOverPlayerSownPlants>false</canSpawnOverPlayerSownPlants>
</li>
</comps>
</ThingDef>
-<ResearchProjectDef>
<defName>VeilPlantsSowing</defName>
<label>VeilPlants Sowing</label>
<description>description</description>
<baseCost>1000</baseCost>
<techLevel>Medieval</techLevel>
<researchViewX>4.00</researchViewX>
<researchViewY>4.20</researchViewY>
</ResearchProjectDef>
</Defs>